You said it yourself. HBO Max as a service will cease to exist. It will be folded into Discovery+ and be called something different.
I didn't say that. What I said was that they're merging. They may rebrand into something else, but that doesn't mean that the content from HBOMax will cease to exist altogether, nor that they'll stop producing it altogether. It remains to be seen what's going to happen, although I do think it's worth being concerned that if you have a pie, Discovery is now going to eat an as-yet unknown number of slices where previously HBO had the pie to itself.
There are also multiple reports that original HBO Max programming is effectively in limbo right now. The things I’ve read suggest their best shows will continue on as shows on HBO itself, but some of the more modestly successful shows may be canceled.
Some of the programming is, and some isn't.
HBO has, for the last 30 years at least, had its own original programming and films made by the network for the network. Unless HBO as a cable service is being shut down and/or transitioned into reality garbage, I doubt they'll get rid of that altogether. And if HBO continues to exist, then it stands to reason that they'll still have a streaming service equivalent.
Personally, I find it....kind of difficult to believe that there are people out there who want to pay for a subscription service to the Discovery Channel of all possible outlets. So, what would make sense to me is that they shut down a bunch of HBO's more marginal performers (e.g., shows and films that are reviewed decently but don't become mega-hits), and devote the money they save from that to propping up Discovery channel's stuff. In other words, HBO-ish content becomes a backbone for Discovery. And at the same time, the money and views they get from Discovery -- and the amount saved by producing dirt-cheap reality crap -- props up HBO-type stuff.
But what do I know. This whole thing just seems monumentally stupid and like the kind of galaxy-brain shenanigans that finance bros and C-suite dipsticks come up with as a "brilliant plan" right before they declare bankruptcy and run away with piles of cash.