To be fair, finding missing galaxies sounds awful close to finding unaccounted for matter. I would call this a not-at-all tenuous connection.
I'll take it a step further. We can manipulate people's ability to see better or worse by messing with their eyes, optical nerves, and occipital lobes. Certainly no one would contend that the "real" world therefore doesn't exist.
I cannot conceive that anybody will require multiplications at the rate of 40,000 or even 4,000 per hour ... -- F. H. Wales (1936)