Tablegen: Instruction 'Predicates' vs Pattern 'Predicates'

Starting off with the question: Should Pattern objects (standalone match rules that are not part of an Instruction definition) inherit the Predicates of the Instruction(s?) referenced in ResultInstrs? Is there a counter-example where a target would want to match and select an instruction, even though the instruction is illegal in the given configuration?

I found a somewhat relevant email from back in 2019, “Please expose predicates to MachineVerifier” that has the quote: “…currently, at least for some targets, we use Requires predicates on instructions which are legal, but we don’t want the TableGen’ed isel to select for some reason.” This seems like the inverse of my question, and logically makes sense. However, selecting an instruction which isn’t legal does not make logical sense to me.

My experience which prompted the question follows