It's certainly possible. But Im not sure the incentive for that to happen is there. I don't think running a mint with ever be that profitable as it's to easy (will be too easy) to create a competing mint naturally leading to many small mints that users will be able to choose from. How users choose remaines to be seen, how much the trust the operator(s), if or what fee they charge, etc. I think it's fairly likely to go through a phase of only a few mints in early adoption but in order to be successful it will reach many smaller mints that have to compete.