I think the standard of "future stuff" applies mainly to how politicians will act in a given circumstance. It would be off-topic to ask if Boris Johnson would rejoin the European Union, for instance.
The key word here that differentiates is contingency. We do allow questions to be hypothetical if they are about if a government has a plan should X happen. So ...
Was I wrong to VTC this question?
No, I don't think you were wrong, for exactly the reasons you give.
Having said that, I think that @ohwilleke wrote an excellent answer that rescues the question. Therefore I don't see enough reason to VTC myself at this point in time. (I would have without that answer)