Haven't they already? After FM released we got weekly challenges in GT7, in which it seems many of the events that may have been permanent additions (considering all the work put into the AI cars) became one-week limited events, while our new permanent events tend to be some flavor of Sunday/Clubman Cup and WTC X00 (but not the fun, longer WTC events with variable weather).
We haven't had a new permanent event category since the Jimny Cup was added in November. The Jimny Cup events are exactly the type of thing we are seeing with the one-week events, like the classic Tourist Trophy events featuring Audi cars becoming a few scattered one-week events that we can no longer play, or the tuned up Renault 4L events that came and went. They were fun, most people seem to enjoy most of the special events, but then they're gone forever.
But hey, new Japanese FR Challenge where you win by participating and not driving off the track more than 3 times. That's a totally worthy addition to the game's collection of permanent events where a win is nearly guaranteed if you simply try.
With GT7's permanent additions being absolutely nothing new or interesting and their temporary additions being fun and challenging events, I wouldn't say they're doing anything better than FM. Both need to give up on the FOMO garbage.