A little. He used these effects early. The delay thing is obvious (can happen by accident) and easy because the playback head is different place from the record head, for a little latency and delay.
I have heard about four dozen LP sides in my life an are very familiar with most. I don't recall any using a flanging effect.
Lots happened from LP using tape (he didn't start with tape, he started lathing discs) and the Echoplex, most notably the Mellotron, which probably has more of a direct link. You'd probably need to ask the Echoplex inventors what their inspiration was, though.