DAX Formula for Cross Table Filtering / Date Logic

Yeah. You might want to define it first as a variable though.

Count90 =
VAR DynamicDate = [DynamicDateMeasure]
RETURN
    CALCULATE (
        DISTINCTCOUNT ( 'Pass'[Customer] ),
        Sale[Created] > DynamicDate - 90,
        'Pass'[Status] IN { 1, 2 }
    )

How about this then?

CountLast90 =
VAR DynamicDate = TODAY () - 90
VAR StatusVals = { 1, 2 }
VAR AddCreatedCol =
    ADDCOLUMNS (
        'Pass',
        "Created", LOOKUPVALUE ( Sale[Created], Sale[ObjID], 'Pass'[SaleID] )
    )
VAR PassFiltered = FILTER ( AddCreatedCol, [Created] > DynamicDate )
VAR AddLastCreated =
    ADDCOLUMNS (
        PassFiltered,
        "LastCreated",
            MAXX (
                FILTER ( PassFiltered, [Customer] = EARLIER ( [Customer] ) ),
                [Created]
            )
    )
RETURN
    COUNTROWS (
        SUMMARIZE (
            FILTER ( AddLastCreated, [Created] = [LastCreated] && [Status] IN StatusVals ),
            [Customer]
        )
    )