The rumor makes little sense to begin with.
There was quite a huge time prior. The first drafts are from 2019, or even before that if I'm correct. So sans 2020(of which they had a few months as well) they had the majority of 2021, part of 2020 and part of 2019 to work on the car.
The likelyhood that a team would not make these first tests is already quite small, considering the significance. The chance that a well-funded team that dropped 2021 quite early on would not make it in time is close to none.
Now, if they don't have all the final parts on, that is quite likely for every team.
There have been no reports of failed crash tests or other turmoil in the team. There is literally nothing to suggest that this rumor would be true.
"Bite my shiny metal ass" - Bender