Are you new to professional sport? Lance Armstrong was, by far, the most tested athlete in history (by various bodies) and he never failed a drugs test. You need to learn how ineffective anti-doping governance is, as well as how corrupt it is.
I think this is the real reason behind Canelo's late notices for opponents. The team have to wait until he tests clear before going into camp, so they delay on finalising the fight, not for the advantage in training schedues, though they'll happily take it, but so that from the start of the testing period they know the Mexican beef is out of the system.
How are the NSAC HONEST & unbiased ?? How could they state this with a straight face " MR Mayweather did nothing wrong we will not be investigating'" This was after Floyd had been caught red handed breaking THREE of the NSAC 's own rules on saline drip for claimed dehydration. c'mon man do they think all fight fans are that naïve !!!! LOL
When Canelo tested positive for Clenbuterol, the boxing commision made him have to test at anytime they asked up to his rematch with Gennady Golovkin. Canelo looking leaner in his leadup to the Golovkin rematch had members of this very forum stating he leaned out because he was off the PED's, that Golovkin was going to tear him a new A-hole. Teddy Atlas went as far as to state that Golovkin was going to obliterate this leaner possible PED-less version of Canelo. The rematch came and to everyone's suprise it was Canelo taking the fight to Golovkin and pushing him back almost the whole fight. Your theory that Canelo waits to announce fights until the PED's taper off does'nt hold water at least as far as the Golovkin rematch is concerned because he was getting VADA tested all the way from the time he tested positive for Clenbuterol to fight time for the Golovkin rematch.
Its more the pattern of recent fights rather than the period around the Golovkin rematch. The spotlight was on him quite strongly back then and multiple peoples reputations were on the line with murmurings of investigation etc.