Some suggestions:
and this may cause a contagion effect which will take down other sites which accept deposits.
Not "may", but rather "already is". Various exchanges have already frozen assets and halted withdrawals.
If you also need to store altcoins,
Trust Wallet is a good option.
Do not recommend Trust wallet. It is closed source and owned by Binance. Given that FTX's apps became malware in the days after their insolvency, recommending any software owned by a centralized exchange should be avoided.
Also, note that many DeFi systems are either fundamentally centralized despite using DeFi tokens/contracts and are therefore about as risky as online wallets, or they are potentially vulnerable to the FTX contagion due to the way that they're designed. Avoid depositing crypto in any service that promises you a monthly or yearly yield, because those services are inherently unstable and are vulnerable to collapse, such as Celsius.
I would remove the second sentence as it makes non yield projects sound safer by omission. I would also expand to cover centralized altcoins. Perhaps this:
Also, note that many altcoins, tokens, and DeFi projects are either fundamentally centralized and therefore as risky as centralized exchanges and online wallets, or are equally vulnerable to the FTX contagion due to the way that they're designed.
Don't add any more. Too long and people don't read it.