Ok let me rephrase - did he not want to have a central office to raise money for shluchim?
Yes. I don't know if the "policy" is outlined anywhere, but it certainly aligns with the Rebbe's approach in general, which is to empower each individual. When each community is self-funded, by definition it will be self-sustaining. It also requires and empowers the shluchim to have to sustain their community, and when the community in turn is invested in the shlichus, that further strengthens it. If Shluchim got funded from HQ, shlichus would be more like a 9-5 job than a life mission.
ETA: The Rebbe did contribute to causes, events, and institutions to encourage, launch, or support them, sometimes from his personal funds, and sometimes from Merkos funds (Merkos is the organization that (mostly) oversees shlichus). It was rare for the Rebbe or Merkos to bankroll an entire campaign. The exception being Merkos Shlichus (AFAIK), and even that is not entirely funded by Merkos these days.