move category and minfreespace to beginning on the options. I am pretty sure they have to be before "defaults". Otherwise, they are ignored. Or just remove default all together.
I solved it! Thank you and gderf for all your help.
I noticed that if I ran mount -a after booting that the mount would work, so the problem wasn't the entry in /etc/fstab as I had believed.
The problem was the order of operations in systemd. By adding x-systemd.requires-mounts-for= for each of the drives to be merged together, the mount finally works! My working fstab entry is below
/srv/dev-disk-by-*/media* /srv/mergedfs fuse.mergerfs category.create=mfs,minfreespace=10G,defaults,nonempty,allow_other,direct_io,use_ino,x-systemd.requires-mounts-for=/srv/dev-disk-by-uuid-7e3d4e5e-228e-47cd-ac2c-77e7f9c1f64e,x-systemd.requires-mounts-for=/srv/dev-disk-by-uuid-2d0face8-47a8-492a-a2fb-f50bcd2826c5,x-systemd.requires-mounts-for=/srv/dev-disk-by-uuid-02c39460-394e-4bec-aecd-33fade3843cf,x-systemd.requires-mounts-for=/srv/dev-disk-by-uuid-dc17cfe1-1df5-4a88-941a-7f90bfd1b071 0 0