My view in the "next" vs "this" confusion is that it's lazy English that had become common usage that's caused it.
Clearly the dictionary definition of next is the next occurrence. There's no latitude for which week you're in to confuse things.

My view is that it started as "this week Thursday" and "next week Thursday" and the week part got dropped as happens very often in English (shop "open 24 hours" strictly means after a day it's opened it's closed. "A day" got lost somewhere!)

I suppose the answer is to be very clear on what is said and not assume that local idioms are understood by everyone.

Another example is time where half three can be half past three or half to three (half past two) in some areas.

English is ever evolving!!