Not sure if it is like that because I'm in Korea, but on my Samsung S9 Samsung is injecting ads for their new S24 in my notifications. I've had the phone for 5 years and this is the first time I see ads in my phone notifications, unbelievable.
Maybe it's because I don't have a flagship Samsung model, but I'm lucky enough not to get ads for their products in my notifications. That, or it's because my service provider doesn't want Samsung advertising new phones, which is a very fat chance that's true.
It's a setting. I believe it's under security and privacy. Mines been off since forever, but I'm not sure if I turned it off right away or if it came like that.
I have an unlocked Galaxy S21 that I bought off Amazon, and I've never seen an ad for a new phone in my notifications.
My first thought was maybe the ad was from OP's service provider, not Samsung, but it definitely looks Samsung-generated. Not that the providers wouldn't do the same thing...