Trump just asked his audience:

[Ms. Toad]

8. Not exactly.

At issue was the narrow question of whether the court could - essentially - force the pardon on Burdick by forcing him to provide incriminating testimony after the president had pardoned him (prior to a conviction).

What the court determined was that Burdick had a choice - he could not be compelled to testify against his own interests merely because he had been pardoned unless he chose to accept the pardon. He could claim the 5th (without accepting the pardon) and refuse to provide incriminating testimony OR he could accept the pardon (entering it into the court's record and implicitly acknowledging guilt) and be forced to testify.

In this case, Arpaio has already been found in contempt, and the case you cited only stands for the proposition that he can plead the 5th, rather than accept the pardon and testifying without personal risk. Yes - if he accepts a pardon it implies guilt, but here there is no particular reason for him to do so (since there isn't - as far as I know - a case out there in which his testimony is needed). He can just leave the pardon hanging out there.