imho, just as likely to be that they would have needed post strike inspections at next landing. Maybe Ryanair don't have full facilities at Alicante? Maybe those checks could have resulted in the aircraft being AOG?
Diverting to one of their bases for that check to me seems a good decision. Minimum disruption to the airline and the passengers.
Could be more than a check. Had one once and a repair was needed. Definitely a maintenance base issue: plus a large base is likely to have more a/c and SBY crews etc. to whisk the pax on their way.