💀 Who is at risk?

First of all, medium and small exchanges that do not have giant reserves and that have actively engaged in risky activities (lending without sufficient collateral, high leverage rates).

Conclusion: Your assumption is correct. The fact that altcoins continue to fall while BTC struggles to hold on may be an indirect sign that exchanges are already actively selling off altcoins to maintain liquidity. When this source runs out, we may see "wildness" live.

The only protection in such a situation is to keep your main assets not on the exchange, but in your own wallet, where you control the private keys. What you do not hold on the exchange, it will not be able to use for its operations and cannot block.