The rumors that concerned a Monster Hunter World announcement included a statement that Sony paid off Capcom to prevent new Monster Hunter games being made for Switch. Each passing month without a MH announcement for Switch adds more credibility to this rumor. That would also be by Monster Hunter World is impossible on Switch, according to Capcom. Not because of technological hurdles, but contractual ones.
This is the first I'd heard about this rumor. But after a quick Google search this is what I found specifically:
While it has been stated previously, Capcom's management was once again asked if there were any plans to port Monster Hunter World over to Nintendo Switch during a shareholders meeting. The answer was simply "no."
However, when Capcom was asked if it would consider developing a new Monster Hunter game that could be popular with high-school kids, the company said "yes."