I actually think Landorus is less threatening than on the regular ladder even though the metagame lost a few good switchins in Mega Latias and Mega Charizard Y. Yeah sure balanced teams struggle with it (especially because the AoA set is by far the most common on the ladder) but they don't have bigger issues with it than on the regular ladder for a few reasons. The obvious one is of course that you don't have to prepare for the megas, leaving you more room for finding a Landorus switchin / revengekiller. Pokemon such as Gyarados, Dragonite and Mamoswine are a few examples of pokemon that have increased in splashability on this ladder as they don't struggle with megas that much while being excellent Landorus checks.

What did (semi-) stall even lose as Landorus checks besides Mega Latias? (which is not even that common btw) They still have access to SpD Gyarados, Mandibuzz, Chansey, Tornadus-T and Talonflame to name a few very good checks. I am not saying Landorus shouldn't be banned, neither am I saying that Landorus should be banned, but it is definitely not as good as on the regular ladder from my experiences both battling against and battling with it. I think Azumarill is a bigger threat than Landorus currently is for obvious reasons (better matchup vs. offense, lost many checks, checks some top tier threats and knock off)