The original mod was never removed iirc, just a new paid version was introduced with more features.
I believe that could be the best possible strategy for TW as clearly the company is lacking resources to implement every feature, required by the community and is constantly criricized for picking wrong priorities. So TW focusing on developping BO analogue will immediately cause a ****storm from sinlgeplayers, as it will most likely mean that their concerns about the game would be ignored.
The BO mod in its current state is a perfect example of EA, showing great potential (with 1000+ people playing on one server) but lacking content and as it seems even a well-laid concept/roadmap of development. It is impressive as an indivudual modder work, but if this was sold by TW that would be quite frustrating. So letting it be developped further by the modder it a safe strategy, later TW may negotiate an official release of this mod as DLC. Paradox did hire the developer of one of the most popular CK2 mods (and TW did it too
) and both let the mod exist at the same time selling more polished (and constantly supported) version of it.
Hopefully the mod really have the potential to be developed, because Warband's official mods kinda sucked bug and balance wise.