Possibly bug in CpsScmFlowDefinition, or a Stapler issue.

Install Pipeline and TFS Plugin. Create a Pipeline job. TFVC is offered in the 'Pipeline from SCM' when it shouldn't be, as it's missing the checkout(Job) override (and doesn't override isApplicable(Job)).

Configure 'Pipeline from SCM: None", Apply, and reload. It will select Git, as it's the only applicable one now (NullSCM isn't either).