Nice theory. No telling WHAT black projects the intelligence agencies wanted to keep under wraps.
But
two written request from President Kennedy about UFOs were revealed in documents (no theory) released by C.I.A. under a FOIA request, back in 2011.
One, asking CIA to provide a list that would delineate legitimate black projects from true unknowns (UFOs).
The other, telling NASA officials to cooperate with USSR on the subject of UFOs.
Memo dated Nov 12, 1963, 10 days prior to the Dallas tragedy.
The conjecture was over a USSR launch of
Zond-1/Kosmos-21 on Nov 11, 1963 (launch failure was one day prior, to date on JFK memo).
The vehicle payload remains classified to this day. Due to some failure, the spacecraft was left stranded in space.
Was the JFK memo prompted by this failed USSR space mission? It is possible.
Was the JFK assassination related to these memos, and the information they would have revealed? It is possible.