Lit Mace Windu ALIVE!!!...according to Samuel L. Jackson anyway

Yep- and he's even missing the appropriate limbs, has what is likely lightning damage, etc. He was even pursued by Vader from Corsucant, for there would be no way Vader and Palps would not try to verify his demise. Mace could be assumed to have found transport offworld, and went there to either get lost or, knowing Windu's combative nature, to find other Jedi, such as Obi-Wwan, who is also known to have been around Nar Shadaa. Vader could have heard about Obi-Wan or Windu being near Nar Shadaa and decided to follow him there, only to find Mace Windu. Vader destroyed Windu in his fighter, and presumed to have finally killed him when Windu's craft was destroyed and went into the gas cloud where the Ganathans live. Mace would have lost a large part of his connection to the Force with so much of his body wrecked, and very appropriately become every bit as much "more machine than man" as Vader.



Besides, Palps instantly recognized who "Brand" was upon their final encounter:

 

I meant SLJ my bad