Agreed that rescinded offers are not something to worry too much about. And, worst case scenario, you can often go back to your old team if you left on good terms.

It would be nice, though, if you had some certainty of some support, though switching jobs inherently entails some risks. If you're recently hired and there are to be layoffs in the next month, you will absolutely be on the chopping block. I'd love there to be something like unemployment insurance, except effective immediately such that spectacularly bad luck while switching jobs doesn't ruin you (and ideally that imposes some penalty on the hiring employer, who recklessly hired you and put your well-being at risk) and large enough to maintain people's fixed costs. That's more of a <10% risk in a down market (I'd guess... <1% in a good market) than a plane crash risk.