One of the trends that seems common is when a manufacturer will completely discontinue parts for a certain model. They tell you they lost the parts supplier, the molds are gone...

I think its a bit more intentional than that.
Either way, your buggy that was 100% fine for the track up until that announcement has suddenly become a collectors item, shelf queen... and you need to buy a new buggy.
TLR discontinued their entire race program. Seems like they don't want to race any more.
I am building an Optima Mid from 1987.
I'm modding it, building it to compete on a track today. No idea if it will do well or not. Haven't run one on a track in decades.
I am never gonna be the worlds fastest anything or compete on any international level... in other words, win or lose, I'll be the happiest guy at the track running my favorite car from 40 years ago. Don't care what AE or TLR says is the hot new set up.
Kyosho has been a solid company for decades.
If online parts ordering, being a little different in the crowd works for you, maybe consider a Kyosho RB7.5.
PR Racing is another company that looks really good but isn't main stream. No idea how parts coverage is on these guys and would be the first thing I looked into.
I still have my gold pan too.
I don't like AE's parts coverage. I think their cars are pretty good still tho.
Have you been to a local track lately just to check the place out. You might get an idea to run in a class you never considered before.
You can also get an idea of what everyone else is running and why.