I thihk you'll find it's MATZ active as per published hours, ATZ within the MATZ active 24 hours (apart from a couple, Barkston Heath being one, plus another which escapes me).
As RAF airfields have ATC, then Rule 39 states you cannot enter the ATZ without permission from the appropriate ATC unit. So - ATC not manned, no permission, no entry into the ATZ even though MATZ transits when closed are not a problem.