If they are following the Clone Wars canon, then Boba Fett is very familiar with Tatooine already. He set up a bounty hunter syndicate as a teenager there called Krayt's Claw and operated from there as he tried to kill Mace Windu to avenge his father. So it seems as good a place as any to hang out after he escapes the Sarlaac.
I have had a lot of wild tangential thoughts about Fett in the past few days that I'll throw out for discussion.
1) He might have suffered some sort of brain damage or memory loss in escaping the Sarlaac and not have the faintest idea who he is until he happens to see Mando drive by and seeing the armor jars his memory.
2) He might have been in his armor when the Krayt ate his Sarlaac and that's how he got free. He might even have a certain reverence for the Krayt as his savior and be pissed that it just got killed.
3) If his mind is intact, he probably knows more about Jedi than any other being currently alive in the galaxy beyond Luke, Ahsoka, and Chewbacca (ROTS fight). He was on Geonosis the day Yoda brough the clone troopers to start the war. Now he might not remember Yoda specifically, since his Dad was killed moments later, but he fought Luke in ROTJ, helped his Dad fight Obi-Wan in AOTC, and interacted directly with ANakin, Plo Koon, Mace Windu, and Ahsoka in Clone Wars. The problem is that he hates the Jedi and would probably kill BY if he could out of hate. Or suggest they take him to Luke and try to kill Luke (I will have Luke in this thing one way or another).
4) As someone else mentioned, Boba is a clone. BY is probably a clone based on what we saw from the scientst dude in Chapter 1 and Chapter 3 of the first seasons wearing symbology from Kamino. Kamino had a big battle fought there late in the CLone Wars, but a revisit with Boba and BY and Mando would be pretty freaking sweet, especially if any of the scientists are still alive, or the template is still on file for BY or Jango.
