Equivalent ARIA role for <mark>?

[BigBlueHat]

There's some text in the motivations/purpose to role mapping table which mentions there's a <mark> equivalency role in the works.

@aleventhal do you know the status of that? We can update it if/when its done in time--or just reference that an equivalent role is also sufficient (if/when it exists).

[BigBlueHat]

Think it's just idling at this point: w3c/aria#508

Perhaps more has been discussed than is surfaced there?