I don't think it's clear whether the IRS cares about it or not; it's very possible that for public securities it just doesn't matter. But it does seem definitely like a software bug. The claim that "comparative sales" must be printed on the form regardless of the user's selection is inconsistent with TurboTax's own instructions and with TurboTax's use of a selection menu for the user in the first place (on which "comparative sales" is one, but only one, of the options).
I don't know how this has worked in previous years because the last time I gave stock, I wasn't using TurboTax. It's possible it's not a new change but a longstanding bug, because (again) it's possible that this doesn't actually cause problems with the IRS and that therefore nobody has felt pressure to fix it. But I'm just speculating.
