Huh? Is your argument that it would be bad for Silksong to surprise release next to GTA? Or that indie developers should have planned around the surprise release of Silksong? I really don't understand what argument you're trying to make here.
My argument was that other releases can and do impact sales.
My original point that there is so many things at play, GTA 6 launch date, which may move, together with other things outside of your control, that "planning your release and development around GTA 6" doesn't make sense, unless you're a big company doing a AAA release.