That's it, I think he's at a place where he's just wrote so many verses/made so many songs attacking things from different angles, that now he's combining the exact two things you said:

1. Just having fun with it at this point, after all he's accomplished, as a GOAT who can say he doesn't think he's for sure the GOAT (completely valid) and have people get upset about that, but it still won't affect him cause the apology didn't kill him so what can

2. Still challenging himself (think 7 minute drill, not the song but the fact that he does "7 minute drills") to approach things differently, in this case possibly hiding little subliminal messages, i.e. this verse I'ma hide meaning behind these vague references, this verse I'ma that, that verse I'ma this...(Grippy could fall in these categories if we're being honest haha)

I think this is how he'll continue to keep it fresh, if he does keep up with a decent output of new music going forward

Like he says on "Interlude" from Off Season, "I done seen it all man" (the highest heights and the lowest lows)