As long as there is ranking of players, there will be few if any unranked servers. If one of the maingoals of the game (its a maingoal because its happening all the time, as one of the maingoals is ''killing'' other players because it happens all the time and its the point of it) is to increase your XP people aren't going to play unranked servers because it gives them nothing while others ''progress'' and becomes ''Heroes''.
By playing ranked servers you label yourself. You gain a XP and you gain certain awards. This does not happen on unranked servers, at least not the first option. It may therefore feel more awarding to play ranked - but not because XP means everything, but because its generally a bonus to the overall enjoyment of the gameplay.
This is most likely why ranking is still present in Classic. Otherwise it may have been way less populated than it really is now. You earn your bayonette in ranked, and you're given it in unranked. It makes unlocks and XP lose its value a little bit and its not so special anymore.
Now,
If the criteria of servers who are now labeled as unranked is changed, then there is a risk that the unlocksystem suffers even more., because then player's can make changes that affect the amount of XP you gain, and maybe even enable or disable certain weapons and so on. This will make the unlocksystem less valuable and it will question the whole idea about it. If you have strived for gaining MkB what's the point if its removed on other ranked server? Or what's the point of becoming Hero if another server is customized and use double xp?
The unlocksystem therefore lose its point which really is to award the player. But if these awards can be given the whole point of striving for them is kinda lost. Therefore, I think that for the people who may play the game for this will find it more or less pointless. Especially with the other factor: Botfarming. In other games, like CoD, its easier because players can't (more or less!) manipulate the XP system.
Personally, I couldn't care less, and I could play on unranked all day because it doesn't matter for me. For me its the opposite: if I gain XP, or any unlocks or perks, I reset my stats. But I know many people don't feel the same. Hence why unranked servers is dead.