Not true. The fall of HDDVD was due to some major porn studio (I don't know which one) siding with Blu-ray over HDDVD. Shortly after that, Wal-mart chose to only stock Blu-ray, effectively killing HDDVD.
Once Toshiba found out about the Wal-mart thing, they pulled HDDVD, giving Blu-ray the market.