The ESP upgrade is automatic and doesn't require any changes on the part of hardware makers. It's also more accurate, according to Amazon, and can change over time as Alexa receives upgrades.

This doesn't change some limitations for multi-device households. Many commands still apply specifically to the device where they're set, such as reminders and timers. Even so, this could be a crucial update for Amazon. If it's going to bring Alexa to virtually every device it can, it has to create a harmonious ecosystem.