Not agreeing with your term of "replacementarianism," but why in the world would you say your fellow Christians would have "extra loss, pain and hurt" because of their disbelief in dispensationalism?
Shouldn't the target of our concern be disbelieving Jews and gentiles?
Not near enough of a prophet to know the particulars, specifics . . . perhaps even in very general terms.
I just feel it in my spirit, in my bones fairly intensely.
I think one way might be lack of preparation of heart, mind, soul and substance.
Another will be a deer caught in headlights effect for far too long when decisive Spirit led actions need to be implemented immediately in situation after situation and the deer in the headlights effect is still immobilizing. Holy Spirit will have to zap folks heavy duty to wake them up . . . or move them bodily or some such. How often He will make that a priority, I don’t know.