I don't think Garcia-Thurman does better than Canelo-GGG. Not even close. Canelo could do more on a PPV than both Garcia-Thurman together. Add in I think one of, and maybe the only fight not involving Mayweather & Pacquiao, that the casuals know IMO is Canelo-GGG.
To add with what
@LauderdaleBoss was saying, I think Pacquiao has some fights that can do really well on PPV...I just don't think they'll happen. Possible fights to make and/or rumored that would make Pacquiao PPV relevant again: Garcia, Broner, Cotto, JMM, and Canelo...maybe Thurman. If it isn't one of those names, I think Pacquiao's PPV numbers will struggle because the casuals aren't as interested in him anymore.