No, it would open gateway to massively bloat Bitcoin blockchain at relative low cost.
And that cost will be paid only by upgraded nodes, so they can do that, if they want to. The rest of the users will still enjoy 4 MB limit. And then, if it will turn out, that all quantum FUD was unjustified, and there is no danger, then these new nodes will have their own bloated version, which they voluntarily picked, so they can leave legacy traffic unaffected.
I get your point. Although the fact there are blocks that contain QC-resistant signature means some mining pool support the upgrade.
Ordinals hype in past have proven this.
Only Segwit nodes are affected by Ordinals. Old, legacy nodes, see smaller blocks in practice, when witness space is fully filled. And the same will happen, if Ordinals will move their data into quantum signatures: we will see smaller than 4 MB blocks in witness space, which is good.
It's not fully true though, since non-SegWit node still store TX created by Ordinal without witness data.