I didn't know about this change, this is actually good news, it means no app can realistically rely on strong integrity as it will cut them from their user base.
Attestation as a signal doesn't have to be used as a binary yes or no decision. Weaker integrity could result in lower rate limits for example.
I think you overestimate how far apps are willing to go for stupid reasons.
Also, there is still the DEVICE_INTEGRITY check that verifies the hardware side of things so if old devices have to be pushed, app developers still won't let you run their apps on LineageOS