The founder pushing employees to take such a reckless financial decision while presumably their only insight into many key business metrics is the leaderships rosy portrayal of them is unethically irresponsible.
At this scale/valuation of the company, it's probably a bad idea but hard to know at the time.
My understanding of US tax laws and options is that this sort of behavior is what you want for early stage startups. You allow early exercise, restricted vesting with the upside of paying no income tax now, only LTCG on vesting (+liquidity event), and potentially QSBS tax exemption if you joined early enough and the startup does well.
QSBS cutoff is $50M in gross assets owned by the company, not $50M valuation. There are many cases where a valuation can be far above $50M yet still qualify. That said, I have no idea if Bolt would qualify here. FWIW financial services companies don't qualify for QSBS at all, so Bolt may fall under that
You missed one important insight: the founder pushing employees to buy shares. That's a red flag on its own. If your options expire, that's less dilution, so there isn't really an incentive to get employees to exercise other than raising funds and the appearance of internal confidence.
Responsible leadership will give you numbers, but leave you to make your own choice. Anything else should make you worry.