Starting to take preorders knowing full well at that point the game was going to be delayed.
Much better than what OP said, especially since they provided no link to a source for their claim.
This is a troubling point that you raise. The time difference between them putting Odyssey for pre-order and saying that it was coming early 2021 only for a month later to say its going to be longer.
I suppose it all depends on how much you are willing to be flexible over what they meant by early 2021 and the revised early spring.
On the one hand, if you took it to mean Jan/Feb and are skeptical about early spring being March/April, then yeah, that's not going to sit well.
I was a bit skeptical about the early 2021 statement anyway, so to hear it might be April or later is no shock for me. But someone who bought the alpha expecting earlier... yeah.
The good thing is, anyone who is disgruntled with this news, at least if they are on steam, can cancel their order and rebuy later.
On the other hand, if they are want to take part in the alpha anyway, then they might as well hang onto it.
PS: Never buy anything on preorder unless you know full well the risk is on you, not the publisher. The reason devs do preorders is because people buy them. If you buy preorders then complain, well, sorry, you're part of the problem, you're fuelling it, and i bet that despite some people getting annoyed with the delay will rush out and preorder the next thing that catches their fancy.