Yeah I totally get those concerns, I think for custodial wallets giving users the option to receive these messages or setting a limit would help, while those with their own nodes can already do that

I think the potential for abuse sorts itself out, people won't post satograms if they don't get a return in engagement and traffic, and if people want to farm LN wallets let them, doesn't look like a good use of time, but hey let people find that out on their own