In a push to improve diversity at District 15 middle schools in Brooklyn, Mayor de Blasio last week approved a plan to remove admission standards at all of them.

In liberal Park Slope and the surrounding areas, the news was received with mixed reactions. Those against the plan were quoted anonymously in various news outlets, lest they somehow appear to oppose diversity. They had seen what happened to Upper West Side parents who were named and shamed in articles when they opposed proposals for their schools.

The announcement of the changes featured some blatant doublespeak. “The District 15 middle-school diversity plan will remove screens from all middle schools and will prioritize 52 percent of sixth-grade seats for students from low-income families, English-language learners and students in temporary housing.” Got that? They will remove screens and replace them with other screens.

The removal of standards won’t just be academic. Schools that previously focused on music or the arts will no longer be able to audition students. Students who have dedicated their lives to learning to play the cello will be in classes alongside kids who have no interest in the arts at all.

The move also pushes off dealing with the real problem: Students are arriving at middle school from failing elementary schools and are unprepared for the tougher curriculum. Alina Adams, of NYCSchoolSecrets.com, and author of “Getting Into NYC Kindergarten,” told me, “On paper, the school will look integrated, but it will remain striated in practice. Not to mention, it will give the mayor and the school chancellor a Get Out of Jail Free card when it comes to improving K-5 education for minority and poor students. [They’ll say], ‘Those schools are already doing great. Look, their students are getting into “top” middle-schools!’ ”

The mayor has taken great lengths to separate himself from the creation of the plan. He tweeted “District 15’s diversity plan is so powerful because it was created by the community.” But Leslie Brody in The Wall Street Journal noted that “a community survey of District 15, conducted as part of developing the proposal, found that 58 percent of 879 respondents favored letting middle schools use academic records to determine who gets in.” Parents aren’t actually in favor of having no standards — but when it’s tied to improving diversity, there’s only one correct answer allowed.

One Park Slope dad told me he sees the move as a “prelude to breaking up the specialized high schools.” He added that the plan would “put the academically struggling kids in schools where ‘magic dirt’ makes kids smarter.”

News flash to our elected officials: Removing all education-based entrance criteria for middle schools won’t miraculously lead to great schools for all, though it’s unclear if that’s even the goal.

Matt Welch, editor at large at Reason magazine and the only District 15 parent I spoke to who allowed me to use his name, told me that he attended the “big mid-August meeting at the Brooklyn library that was billed as being for parental ‘feedback’ ” yet anyone who wanted to speak against the plan was silenced and “the first mention of whether this would actually improve the schools came 45 minutes into the meeting.”

The move may not even lead to more diverse schools. What will more likely happen is schools that were once considered strong academically will have to reduce their educational standards as they accept students not on merit but on luck. The final diversity plan for District 15 lays out the history of the middle schools in the district. In the late 1990s and early 2000s, white people mostly opted out of the public middle schools. Once screening such as testing, grades and other factors were introduced, parents returned to public schools in the area. Now they’re poised to leave again.

But this has nothing to do with race. A study earlier this year found that forty percent of the city’s kindergarten students go to schools outside their zones. That included “fifty-nine percent of black kindergarten kids.” Parents will do whatever is best for their children academically.

Adams told me, “In my experience as both a school consultant and the parent of African-American children, New Yorkers don’t mind going to school with racial diversity. They don’t mind socioeconomic diversity. What they do mind is academic diversity. And that’s the one that can actually be changed!”

Those hardest hit by the changes will be middle-class parents who can’t afford to send their children to private school.

They may make a mass exodus for the suburbs or charter schools may see an increase in applicants.

The announcement of the admissions change was made at MS 51, an in-demand middle school once attended by both of Mayor de Blasio’s kids, as well as the children of Councilman Brad Lander, also a supporter of the plan. Neither man explained why they hadn’t chosen a more diverse option for their own children when they had the chance and instead went with the whitest middle school in the Park Slope neighborhood.

“My family has benefited from that privilege, and we’ve got to honestly look at it and be willing to talk about it,” Lander said.

Lander and de Blasio could have had a more academically diverse school for their children, but talking the talk for other people’s kids is different than walking the walk with your own. They might say that they didn’t mean to choose the least diverse school, they just chose the best educational option for their kids. That’s something their constituents in District 15 will no longer be allowed to do.