I don't really understand what this is about. My braincell was consumed in the other proposal. I just want to say something about this:
"if you really want to let older cards maintain some use case, then it would be better to keep"
Why won't we errata the older cards and buff it? I normally quote Yugioh regarding this. In Yugioh, they have a ban list for certain cards. While these cards are techncally useless since they cannot be used, some still collect it because there are times they were allowed. Raigeki, a card that destroy all opponent's monsters, were banned for like 2 years, I think, then suddenly, it became usable since more cards (after the 2 years) became resistant to destruction effects, therefore, indirectly nerfing Raigeki.
Same as here but the opposite. We can buff some cards and nerf the others. That way, everything is still relevant. Haunted Spirit, for example, if only I can use it in Modern, I would. It is a beta card but even until today, still I think is one of the strongest Death card due to his Heal ability.
So, while the power creep is true, it really isn't true on all cards. I still haven't found a better card than Cerberus for low mana Little League. Actually, even though he is a beta monsters, he even got better with Tarsa, from the Chaos Legion.