<p>It can if Project Insight was covered up. That way, the HWC in Season 5 was never accurate, we just didn't have all of the information, similar to Sousa's death. It was always that they removed him from the timeline, they just didn't know it.
</p><p>There wasn't a mention of Project Reclamation, just May's line about the HWC. If it's rewritten history then history would still correct itself (per Deke in the first episode), so Freddy's funeral would be 1976 instead, and the Whitehall/Gideon cheating stuff would be whenever the next ceremony was, thereby allowing the Hive stuff to happen (again, based on Deke's explanation).
</p><p>Trust me, I really want it to be an alternate timeline, but we also have to consider that it's not. Even if they're rewriting history, Mack is still Mack and has all of his pre-rewriting memories, since he's time-traveling with them. So we can't really turn to him for evidence at the moment.
</p><p>For those of you who watch the DC show <i>Legends of Tomorrow</i>, I think it's like that, where you'll remember if you're also time traveling, but you'll be oblivious if you're in your own time.
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