Way to go Toriyama, for shoving it in fan's faces! I'm actually kind of happy he said that.
Gohan being #1 would have been shoving it in the fan's faces. Goku being retconned to #1 is playing it safe, just like making Goku the hero at the end of the Boo Arc was. It's just lazy writing; if he had followed through on his promise of Gohan being the hero, the Boo Arc would have been greatly superior. He would have had to make his characters
change! Wouldn't that have been fantastic?
DB writers just can't handle character development, hence why Vegeta has regressed to his pre-Majin attitude in Super.
Anything fans make up to explain away black and white statements like "we can't beat Boo" or "if only we could fuse, then we could beat Boo", doesn't mean much when we've got Toriyama saying he doesn't care what happens in the manga, and Super can have whatever he wants because he's the author.
Boo's ki being like a lie has nothing to do with his current power (whatever that may be) being difficult to sense. It's the tendency he has to explosively increase in power for no reason (i.e. you can't tell when he's using full power). There is no way that Goku could mistake Super Boo's power for being greater than it really is, only the other way around (hence why Piccolo thought base Gotenks could win, hence why Dabra thought he could beat Boo, hence why Vegeta thought Boo was trash, hence why Goku can say he might not win against Fat Boo).
Which is more likely?
-Nonsense explanations that attempt to invalidate uncontradicted, black and white statements inexplicably became true.
-Toriyama decided that Gohan is too difficult to use as a character, so he was made irrelevant. (This has happened before)
Boo Arc Vegeta was too difficult to use as well, but you can't have DBZ without Vegeta, so we just decided that he had never changed in the first place.
