You really would be best to ask the person coordinating this program.
She may be using a complete pattern, with the fabric requirements noted.
Also, if she has made the quilt already, then she will know what she has used ... that is, if she has made it!
At the least, she should be able to estimate the requirements, based on what is planned for the year ... or has the full year been planned out?
It really is hard to guess/advise what you may need ....
... do the blocks have a LOT of background in each block? or just a scant amount?
Likewise for the coordinating fabrics ... Do you need two per block? or 6? or? or perhaps choose one constant and do the rest scrappy?
Plus ... will you receive finishing instructions for this BOM at the end?
Should you consider now as to what fabric(s) you may want/need for sashing, borders, binding, and of course, backing.
One of the challenge of a Mystery BOM
I just started a BOM ....... different size blocks and numbers that yours. However, up front we were told the amount of background fabric required if it is to be a constant or if we want an assorted backgrounds, what we need for that. Likewise, some approximations for the other fabrics