No, they kinda did try to hide the price increase on games...or at least mask it behind the new gameplay reveals and announcements (including opening up preorders) at the September PlayStation event. You're definitely misremembering that.
However, as I said before Sony at least did it the "right" way (as right as you could for something like this, anyway). For one, it was a relatively small increase (compared to what MS just tried to pull). And more importantly, they basically "shouted" over the news of the price increase with stuff that was actually good news, i.e Demon's Souls footage, more R&C Rift Apart footage, FF XVI trailer, various other game reveals, opening up preorders etc...
..in fact funnily enough them screwing up the preorders and some assumed PS5 exclusives being cross-gen ended up becoming the bad points for them from that event, so most just kind of forgot about the price increase because it probably didn't register as badly as those other two things.