It would be interesting to be able to open an account with this other method of tax identification, and when it will be available to open a dollar account for users in the UK
Based on this I would say no, at least at the beginning
An EIN is the US tax id for a business. I don’t see any signs of Monzo opening business accounts in the US in the short term, so the answer is almost certainly no. As an aside, when I have opened a US business account with an EIN, I have been additionally asked for my personal SSN.