Craig Woolheater posted a piece on the same subject on Cryptomundo earlier today. Craig asked Cliff, Bobo, and Matt about the rumor. Cliff said:
"No, we aren't cancelled. In fact, we are filming more episodes this summer. The programming folks at Animal Planet have made some decisions about how to best support Finding Bigfoot based on the data, and they are moving ahead with their plan. Luckily this has little to do with me, so I can just focus on bigfooting."
Bobo:
"No, viewers were pissed about the night change and advertisers buy slots ahead of time so they have to go through current cycle. Or something like that. We're filming all summer."
Matt M.:
"Animal Planet is holding the remaining episodes for next season to add to the new ones that they are currently filming in order to air them back on the original air time of Sunday nights."
So no, Finding Bigfoot is apparently not cancelled.