It's true that the AoS rules state that base sizes and shapes are ignored, but the first house rule that most gaming groups adopt is "measure from base".
Certainly all AoS organised tournaments so far have stated in their comp packs that models must be based appropriately. For example the Clash Comp rules included:-
Measure distances from the bases of models to each other.
Bases sizes allowed will be the ones models were supplied with or if you have rebased the model onto round/Oval bases then these must be sensible.