Out of curiosity, how long have these brightness increasing texture packs been around? This almost seems similar to the debate about whether or not BSM should be allowed in 1.7. I honestly can't remember there being these kinds of texture packs in the past, although I could be and probably am wrong.
Anyway, my only opinion so far is that they
both should either be allowed or not allowed. We can't have two things that are essentially the same have different rules. I'm still not sure as to whether they should or should not.