Referrals to the Enlarged Board of Appeal

Does the EPC confer jurisdiction on the EPO to determine whether a party validly claims to be a successor in title as referred to in Art 87 (1) (b) EPC?
If the above question is answered in the affirmative: Can a party B validly rely on the priority right claimed in a PCT application for the purpose of claiming priority rights under Art 87 (1) EPC in the case where a) a PCT-application designates party A as applicant for the US only and party B as applicant for other designated States, including regional European patent protection, and b) the PCT application claims priority from an earlier patent application that designates party A as the applicant, and c) the priority claimed in the PCT application is in compliance with Art 4 of the Paris Convention? (EPO Board of Appeal 28/01/2022, T 1513/17; pending before the EPO Enlarged Board of Appeal as G 1/22)