I'm not sure why it would be dramatically different from today. If I
understand your scenario correctly, the recipient would only provide
blinded paths that go through "regulated" nodes so that they can
witness the payment. Since the recipient agrees on doing that, the
recipient could simply share data with those "regulated" nodes without
forcing payments to go through them? And they can do that today without
blinded paths?
Even if the payments go through such "regulated" nodes, what preserves
the sender's privacy are the hops before the introduction point, that
they can choose freely. This is exactly the same model as freely chosing
the hops to the recipient directly (when not using blinded paths). Apart
from the loss of potential payment routes for the recipient, it doesn't
look like the sender's privacy is very different?