iOS 15.1 beta 3 test so far is inconclusive. One app got some limited background processing time, but the test is confounded by having Background Modes checked for Background fetch and Background processing. Disabling those now. The other app, which works fine on iOS 14, didn't get any processing time.
default 11:12:21.732196-0400 dasd com.apple.healthkit.background-delivery.tld.domain.app1:094E1A:[
{name: ApplicationPolicy, policyWeight: 50.000, response: {Decision: Must Not Proceed, Score: 0.00}}
], FinalDecision: Must Not Proceed}
default 11:12:21.732573-0400 dasd com.apple.healthkit.background-delivery.tld.domain.app2:F09C36:[
{name: ApplicationPolicy, policyWeight: 50.000, response: {Decision: Must Not Proceed, Score: 0.00}}
], FinalDecision: Must Not Proceed}
default 11:12:21.734499-0400 dasd com.apple.healthkit.background-delivery.tld.domain.app3 (production app):53F125:[
{name: ApplicationPolicy, policyWeight: 50.000, response: {Decision: Must Not Proceed, Score: 0.00}}
{name: FileProtectionPolicy, policyWeight: 0.010, response: {Decision: Absolutely Must Not Proceed, Score: 0.00, Rationale: [{classALocked == 1 AND activityFileProtection == <File Protection: ClassA>}]}}
], FinalDecision: Absolutely Must Not Proceed}
Then I got lines like this, but only for the production app:
default 11:27:08.675816-0400 dasd com.apple.healthkit.background-delivery.tld.domain.app3:53F125:[
] sumScores:68.598232, denominator:68.620000, FinalDecision: Can Proceed FinalScore: 0.999683}
default 11:27:39.184446-0400 dasd COMPLETED com.apple.healthkit.background-delivery.tld.domain.app3:53F125 at priority 30 <private>!
