Supertech vs. Syntec (O'Reilly)

I bought a jug of M1 5W30 (Dexox 1 Gen 3) for $24 and an Asian made Microgard Select oil filter for $9, for my next oil change.
Same, plus there was an $8 rebate on the Mobil 1. Got it in less than 10 days. Used an OEM filter I get for about $5.50 in bulk. So , $33 for store brand oil and filter seems high to me. YMMV.
In all of my old GM vehicles i get a noisy- piston slap- startup with a 5w30 that is not there with a 10w30. I run a 10w in them year round in PA w no issues, synthetic or blend or dino never mattered
I wonder how O'Reilly is able to use the Syntec name without getting sued by BP? I'm guessing the trademark expired since Castrol no longer has that name on their labels.