Yeah, if direwolves had been a thing, it might be different.

But traditionally the lions were the kings of the animals, and wolves were little more than dangerous vermin.
Also there are cases where the name of a certain region/city corrupts into something that invites the use of the lion as heraldic symbol, for example León in Spain (name that comes from a roman militar settlement: Legio VII) or Lyon in France (from the celtic god Lugoves).
In any case, wolves were popular in heraldry. They just took a secondary place to lions.
Think of the germanic names include -wulf (-olf in English).
Probably lions were seen more as a symbol of majesty and uncontested power, while wolves were of being strong and aggressive. The monarch and the "jobber".