Yep.
In fact, this could make sense because the PN basically described the Sea Sultan as a multi-mission aircraft. It won't use the Sea Sultan strictly for ASW or AShW, but also AEW and ISTAR.
Moreover, I don't think the Sea Sultan would be as hard-hitting in ASW or AShW as the P-8. It lacks the size to match the P-8's payload options. So, once the PN retires the P-3Cs, it will actually lose a bit of capability, even after inducting the 10 Sea Sultans.
So, as you said, we could see 4-6 of a larger LRMPA (e.g., based on A320), especially if Turkey opts to design and develop one for its own requirements.
@JamD @kursed