This has also been my prediction as well. I think Microsoft has the same idea what with calling it the "Series X", and since games can be scaled far easier than ever before to whatever spec requirement required (to a certain degree), I think it would be a smart move to have a upgrades perhaps every year or two, and new game releases would be required on run on the last two revisions, for example. This means users wouldn't be forced to upgrade for some time, but the console would also not be held back in the long run. It's what mobile phones have been doing for awhile, and it makes sense for a lot of reasons.
Also, there wouldn't be such a huge power gap at the end of life cycles. Games released to this day are still optimized to run on a console that was released in 2013. This is why PC games look so much nicer at the moment.