Probably not. As far as we can tell, the AP only is a gimmick for specifically the British CLs. In a way, you can look at the British line as an experiment in potentially how to handle splitting heavy cruisers (CA) with Light Cruisers (CL).

IMHO what has gotten the majority of people who are upset about the British line to that point is that their feeling that experimentation should be kept on the testing servers rather than pushed into the live environment to see how it fares in the wild. Usually when WG pushes an experiment into the wild it is simply with a premium such as Atago (CA Heals), Kutusov (AA changes), Atlanta (mid-high tier CL viability), Nikolai (accurate BB guns in low tiers), and others. Some of the changes end up sticking (Kutuzov) while others are thrown away entirely (Nikolai).

Using a national premiere and and entire nation line as an experiment is as of yet unprecidented. I am not as mad as some, since I don't think more content can ever be considered a BAD thing even if it isn't really what people wanted or expected, but I am certainly not convinced that british cruisers will even make it to the next patch unchanged. I do think that it is extremely unlikely that the line will be removed though.

The question remains though, whether WG will respond with another gimick, or if they will just give the RN weak HE shells. Right now the RN line has too much of a luck component when it comes to survivability, and exploiting the mistakes made by opponents (both AP and torpedoes are PUNISHMENT weapons, not generally considered competitive weapons against skilled opponents, which is why competitive games always feature ships with strong HE (kutusov / atago), and AA is considered very important (NC / Bismarck AA build AFT+MAA, Kutusov AFT+DE+MAA).