The Jag XK platform had 45+ year run. I'd bet that as long as the 911 is made, it'll have an inline 6 and to someone's thinking it will be the same platform as the air-cooled version from 1964.

Engine architectures tend to last unless they are bad. They can do a lot on one also, the Toyota GR platform started out as a fairly vanilla V-6 but it has variations with GDI and variations with turbochargers and has been used a lot of different vehicles. A lot of different variations with different levels of compressions and such. It's basically the block and cylinders configuration.

I'll shout out the K-series though, it's a shockingly good platform. Lots of little details have been thought through, it's relatively simple, inexpensive and reliable and maybe one of the easiest engines to work on. If you were new to cars and wanted to start wrenching, the K-series is a pretty good place to start. It can take boost and make power and has lots of aftermarket support. I know civics aren't everyones cup of tea and it's not a big V-8, but I've yet to meet an engineer that isn't at least slightly impressed by the k-series.