It does help bitcoin's price, it doesn't changes the fact that those 10K worth of BTC will be off the market
Not only that, but his coins could potentially be used to support LN when it comes to adding liquidity to the network. He bought himself a hardware LN node recently, so it's a pretty realistic option if you ask me.
To make things sound even more bullish, he stated that it's only a matter of time before Cashapp starts utilizing LN. In order to actually make it work in an appropriate manner, they have to open hundreds/thousands of well funded channels.
LN currently counts 774BTC in liquidity, and the way things go, we'll see 1000BTC before the end of the second quarter. That milestone will generate even more positive news and attracts more merchants and users to Bitcoin.