This is what I've always heard/read as well, IMO it has merit. If soil temps can stay up, will lessen the impact of a cool shower. "Here" if soil moisture is adequate, I prefer to be rain free in the 24 to 48 hrs after planting regardless of temps. Seed size has a direct correlation with time needed for imbibe, and is complete when kernel absorbs 30% of its weight.
Wait, see, and evaluate. Hopefully it finds your concern unwarranted. Personally, when evaluating corn stands, I've come to value timely/even emergence of the corn nearly as much as an evenly spaced/missing stand. Doesn't take much of either one, to pay for a replant if needed, it's still early, upper end potential still available. As one friend likes to jokingly quip "Plant early and often!" Good luck.