There are way easier paychecks in boxing than a GGG fight. If a guy has other options, he'll take them.
This is part of the problem with todays boxing environment though. Everyone thinks the other guy needs to be the first to make an offer. Fighter A - Ay you know where Im at, all they gotta do is pick up the phone Fighter B - Im not ducking nobody, all they gotta do is send me an offer and lets make it happen. I don't know how many times Ive seen this play out now between camps who think the other guy should be sending an offer. Is it that hard to just send offers yourselves.