I would be very happy if that were true (and probably Ronaldo would be very happy too as he was able to continue to improve his perpetual record), but it seems to me that UEFA will never go for it. If players from Europe who left for Saudi Arabia retain the opportunity to play in the Champions League, then the flow there will only increase and the situation in Europe will worsen even more.
Such terms must be proposed and need a long time to be approved. Now we only heard about that idea and no official proposal yet so any final approval decision will not come in this summer or even next one. Meanwhile, Cristiano Ronaldo is couting down very last seasons in his career and I mean last seasons at best level. He can play till 50s if he wants like Kazuyoshi Miura, the Japanese player but will he be good enough for Champions League at such age, not.
The next season of the Champions League will already be held in a new format (Swiss system) and I don’t think that anyone would be upset if one more was added to this change. But I understand that you are talking about bureaucracy and of course such changes will not be made so quickly.
As for Ronaldo, I don’t know what form he is in now, but in my opinion, until the playoffs, the level of play will be very low, especially for weak teams (due to the new regulations).