I see no reason why not.

Returning the event shouldn't prevent them from adding new content. I'm not sure why people are saying they'd prefer new content as if it were a choice between them.

It's a grind, but it's also a ton of minions and a shame to lock new players out from them entirely. Perhaps it would be better to just make it permanent like Rathalos so players can take their time and go through the fates at their own pace.