This is a really important design question.
Should we/can we really need to support backward compatibility with java 7 while being able to use java 8, 11, … ?
If answer is yes, then there is no other way than using the maven artifact for any module that is removed in java 8, 11,…
And I think first we need to answer this question, then we can decide which path we should go.
And some experienced person like @pspeed can be the right guy to answer this question.
I am not qualified to answer it, but for me, it is not important to keep with java 7. (I had lived with java 7 only for a few months when I first started programming then soon Java 8 came and I switched to it and now I am on 11) . So I am totally ok with giving up on java 7.