Quote from Millionaire:
Our real-time margin system applies maintenance margin requirements throughout the day to new trades and trades already on the books and enforces initial margin requirements at the end of the day, with real-time liquidation of positions instead of delayed margin calls.
This would clearly seem to affect day-margins for brokers that use "maintenance margin" as "day-trading margin."
I would assume they would just come up with a different day-margin formula - rather than trigger auto-liquidations at the CME Initial Margin amount (which effectively would raise true position-opening margin requirements by an undetermined amount).
Everyone is going to be looking for clarification from their brokers before getting going Monday morning . . (or Sunday night).