I don't think Dybała is considered a striker. He can play there but so he can play CAM. Therefore, I don't think Haland would compete with him directly. He'd get minutes when Ronaldo and Higuain need rest or if he continues his form he would just bench Pipa. Also, assuming Costa keeps injure himself and Berna continues his poor performance, he'd find lots of space upfront.
What is really interesting is that we would have basically exchange Kean for Haland. Both 19yo strikers with Raiola as their agent. Apparently we sold Kean because Raiola wanted more minutes for him. Having said that, would he now sell us Haland if he thought he won't get minutes here? Or maybe it was Juve who decided to cash on Kean because we thought his disciplinary issues will be an obstacle to his development as he's been showing with Nazionale and now Everton? If that was the case then Moise wanting more minutes could've just been a useful excuse to get rid of him for decent amount. Now the Haland rumors show we still want our young super talent upfront.