I don’t know who this rabbi is and what point he was trying to make, but this is an old argument usually used to validate non-frum movements in Judaism. The claim is basically that charedi rejection of modernity (chadash asur min hatorah and all that) is a reaction to secularism and didn’t exist before the 1800’s. Since before then there was no modern culture to reject, that rejection of modernity can’t be considered an intrinsic part of Judaism and is in itself an innovation.
I think this is really just a game of semantics, though. You can call it whatever you want- Orthodoxy, charedism, ultra-Orthodoxy, etc., but in all assential ways frum Judaism today is the same as it was 200, 400, 800, or 1400 years ago. I’ve read that before the enlightenment, the number of Jews who were openly mechallel Shabbos could probably be counted on the fingers. Before then, virtually all Jews kept Shabbos, kashrus, and believed in Torah min hashamayim and the coming of Mashiach, just to give a few examples. If that’s called being “charedi”, then it’s not new at all.
I assume the rabbi giving this speech wears a yarmulke. What was his point?