Yes, it's going to cause a lot of confusion and missed meetings. At the moment everyone says "pacific time", but now that will mean two different things.

I think we'll need to say Vancouver time or California time.

Mountain time is ambiguous due to Arizona, and yet we still use that phrase. Hawaii-Aleutian time is also ambiguous: the Aleutian islands do daylight savings, but Hawaii doesn't.

Casual speech doesn't use the city names (like America/Los_Angeles for pacific time); presumably we'd have Pacific time (America/Los_Angeles) and BC time (an update of the existing America/Vancouver). If Washington's time change ever gets approved it would presumably become simply Washington time (America/Seattle maybe?).

Maybe people will finally learn the difference between PST and PDT.