Hey there! Yes, that's correct! If you go by the Big Daddy Flowchart, a primary leaving group should give you an SN2 or no reaction and a tertiary should give you an SN1 (exclusively talking about substitution products). You can find the flowchart here if you haven't seen it already: https://www.clutchprep.com/organic-chemistry/big-daddy-mechanism-flowchart/?c_id=12017
I hope this helps!