'Excited for' versus 'excited about'

[Apileofballyhoo]

AIBU to ask if this has taken over now and when did it happen?

I would only use excited for if I was telling somebody I was excited for them because of an amazing opportunity they had or something. If I was off on my holidays I'd be excited about it.

But people seem to be excited for things now, rather than about them.

Bloody Americanisms!

People on here say "of a morning/of a Sunday" quite a lot and a/ it sounds kinda Victorian and b/ I've never heard anyone say it in real life

Is that a regional thing?