Perhaps your friend has already been informed or even interested about Bitcoin and crypto. The greeting is basically promoting Bitcoin and crypto.
However, the line "invest in Bitcoin and cryptocurrencies" is just like the tiny tip of something enormous. It entails knowledge; it entails careful research not just of Bitcoin itself but also of how to securely access and keep it.
There must be serious disclaimers following this encouragement or, better yet, precautionary warnings. This is the overused line of scammers soliciting investments from gullible individuals in the name of Bitcoin and crypto.
Good point about disclaimers. I've seen on multiple occasions how people were trying to attract others to the market, but IMO their actions were controversial or even harmful. Namely, in all those cases people were focusing on Bitcoin as a good investment opportunity, encouraging people who have no or very limited knowledge of Bitcoin to buy and hold. I think that it's important to be honest and explain the risks, as well as mention that being an investment option is not the only thing Bitcoin is (because it's also a currency that can be used to buy stuff without using the money controlled by some state).