Of course they would! Old raids are A LOT easier when it comes to tactics, the only thing those bosses had was insane tuning and that doesn't make a boss harder, just annoying. We raided AQ40 and old Naxx without voice com and were pretty good at it. I can't imagine doing bosses today without voice coms and 1000x video guides everywhere + tons of addons. Back then we only had decursive and maybe some recount and that was it.
People who say TBC and Classic WoW were hard are the ones who are too influenced by nostalgia of how better and more awesome it was, with a lot harder bosses to make them feel special, but the truth is way different than what they say it was.