If anything, Uber will save money by not operating. Their cashburn should be substantially lowered if they are not subsidizing rides.
[1] https://benjamintseng.com/2019/04/lyft-vs-uber-a-tale-of-two...
At the same time, this time presents a unique opportunity for their engineering: how often does the market give you several months to breathe? Isn't this the time to polish the product, to finally fix all that tech debt you accumulated?
Based on what? Raise your hand if you're excited about either driving or being driven by strangers now. I think we're looking at several years post-vaccine before one can credibly argue that peoples' comfort with that sort of thing will have recovered to pre-pandemic levels. Ditto AirBnb.