Companies with less than 20 employees aren't federally required to offer COBRA. Companies larger than that are required to offer at least 18 months of coverage. I don't know how large your old company was, but Coinbase is large enough that this offer, rather than being generous, sounds illegal? https://www.dol.gov/sites/dolgov/files/ebsa/about-ebsa/our-a...
I think you misunderstood: Coinbase is offering to pay for the first 6 months of COBRA for the laid-off employees. They can still continue with it for the following 12 months if they want, paid out of pocket.
They're offering to subsidize the cost that the individual would normally pay for COBRA coverage. They're only required to offer the coverage, but not to pay for it.
However, I don't think this is that unusual in SV layoff packages.