[erimir]

That presumes a fact not at all in evidence (and with substantial evidence to argue against it):

That if Democrats had not nuked the appointment filibuster in 2013, Mitch McConnell would've allowed Democrats to filibuster Trump's judicial nominees indefinitely.

I find that incredibly implausible. McConnell did not need Democrats to eliminate the filibuster in 2013. He had a majority in the Senate in 2017, and he could've eliminated it without Democrats' consent. Democrats didn't "allow" Trump to stuff the courts with nutjobs, as if they would've been required to keep the filibuster if not for Harry Reid's actions in 2013. McConnell could have, and would have, eliminated it for Trump.

So if Democrats hadn't nuked it in 2013, the result would've been that McConnell nukes the filibuster in 2017 instead, and all those vacancies filled by Obama after nuking the filibuster would've been filled by Trump.

If your argument relies on Mitch McConnell's respect for norms and the opposition party, your argument has a fatal flaw.