After reading about the new 650B tire size, I started looking around and found this warning over on 29".com and on BRAIN.
Fox Racing Shox Warning to Customers
WATSONVILLE, CA (BRAIN)—This is a warning against unapproved use of Fox Forks from Fox Racing Shox.
FOX 32, 36, and 40 suspension forks (with the exception of model F29) are engineered and tested for use with 26-inch mountain bike tires. These models meet CEN and AST M testing standards based on use with 26-inch tires.
Use of Fox forks with any tire larger than 26 inches, such as a 650b tire, will subject the Fox fork to loads and forces it has not been designed or certified to meet.
Fox 32, 36, and 40 suspension forks are not recommended or approved by Fox Factory, Inc. for use with tires larger than 26 inches, either as original equipment or aftermarket, according to Fox's Elayna Caldwell.
Unauthorized and unapproved use of these forks with tires larger than 26 inches may result accidents, causing serious bodily injury or death.