We dont know whether Moshe and Eli were 'in the flesh'. Just as there is no reason I know of from the text to assume the M27 event is talking about long dead saints. We do know that a fair number of folks were raised by Jesus and the disciples Laz being the best example. As above I dont know of any of those who were reported as having been dead more than 4 days. It seems that if the disciples could have done so at least one specific example would have been recorded.