I'll bet that if a talented team of enthusiasts puts together playermodels, weapons, statics, etc. and especially maps needed for a new front, all meeting both the technical and quality requirements of FH2, then properly apply for their work to be included, the developers will at the very least consider including it in the official build. Tournament maps and tournament minimods are another thing, but aside from those, the only efforts approaching this kind of commitment that I have seen are the French Hope, and the NML modmod (which has official developers partaking).
We have the problem of dozens of people asking for a particular army or battle to be included, and only a limited number of developers, who can only concentrate on a limited number of fronts at a time (read: one in production and one or two in preproduction). Even if the devs bring out a new front once a year, the math is against the likelihood of ever including all the requested armies. Unless, of course, many new people learn to model, code and map on a sufficiently high quality level and apply for their work to be included in FH2.
