If you have the ability to withdraw to your own custody, I'd recommend it if you're reasonably technically literate (which I'm assuming because you're here).
If you don't have the ability to withdraw it, you have crypto IOU's, which is a layer riskier than actually having the assets already.
> Any idea what this could mean for those holding crypto on Robinhood?
Robinhood ain't risking much I think. Look at what the ex CEO of Binance got: a personal fine of $50m (while he's believed to be worth about $30 billion), a $4bn fine for Binance and three months in prison (where he'll be the richest inmate in the US).
I don't believe that at this point there are still people who have their cryptos with them. These people already have “most wanted” style documentaries and almost all cryptos forums have in their FAQs “Not your keys, not your coins" warnings.
RH has been working hard to get regulatory approval, similar to Coinbase. I don’t think anything drastic can be done if they are found to be in the wrong, considering they’ve been proactive with getting regulation in place
They've been reprimanded by a federal judge for blatant extrajudicial power grabs like this one. None of their huge cases claiming various cryptocurrencies are securities have succeeded, except in the super cut-and-dry cases like ICOs and centralized schemes that clearly pass the Howey test.
> in the specific context of staking and promising returns, not crypto in general
Every ruling in the lower courts on these issues will be narrow. The SEC has been on a winning streak recently. The only major kerfuffle was the judge not ruling that XRP is a security, though Torres still ruled in the SEC's favour broadly, and the ruling has been widely criticised (not by industry people, but senior lawyers) for being likely to be overturned on appeal.