Like I told Downeast, look at the past few election cycles in those red states. A lot of what happened there is the same thing that happened in AL when Doug Jones won the AL senate seat. The media screamed it was the state changing Blue! Us Alabama folks laughed and then ole Dougie got the mess beat out of him a few years later like we said he would.
This is probably true for MS Senate, for example, but it's a six-year term, whereas Jones just had ~2 years left on his term after winning the special election if I remember right? Another corollary was Scott Brown winning the special election for Senate in Massachusetts in 2010, then of course he got beaten by Elizabeth Warren in 2012 (although the election was tighter than one might've expected for the state, though Warren of course is hardly an electoral juggernaut, as history has shown).
Also, some people downplayed Republicans losing both Senate seats in Georgia in 2020/2021. Indeed, they probably win both of those if it weren't for Trump's meddling and discouraging voters to vote in the runoff election because of his voter fraud claims. But six years later and it's been all Democratic Senators for Georgia and with Ossoff's huge win on Tuesday, that doesn't look likely to change going forward. The whole state may indeed be on the verge of turning blue with the win in the gubernatorial races, too; it's certainly still close enough to be called a swing state, but with all the elections there post-2020, it's hard not to say it at least tilts blue at this point?
Sure, Mississippi will almost definitely flip back and I'm sure South Carolina will as that was mostly (lack of) candidate quality, but that may not be true for every state that flipped.
Texas could be a state that follows Georgia's lead, but it's really too early to say, I think. It may snap back next election. I think candidate quality was a major concern there because of how terrible Paxton was, but at the same time unlike in South Carolina it resulted in Dems sweeping every statewide race, which is crazy.