That said, they've done this in the past (send a naval fleet out). It's a pressure tactic to make Maduro react and crack down hard on opposition - which the media then represents as a paranoid dictator. At the same time however it emboldens the opposition, and if he doesn't crack down on them and the opposition attempts a coup like they've done in the past then the U.S is ready to step in like Grenada, or Brazil (1964) under Operation Brother Sam.

Theres also the US invasion of the DR in 1965 (the Dominican Civil-War), when the US, Haiti and many of the US puppet regimes armed forces invaded the DR to remove the first democratically elected Dominican President, the nationalist social-democrat, Juan Bosch. Bosch had been removed from power by a Far-Right Military coup, but he had the support of some conservatives and liberals, specially within the armed forces and attempted to return to power. The US invaded to stop their puppet goverment from collapsing.

I'll add to this that there are plenty of valid criticisms of Maduro but it's hard to tell which are forced decisions due to the impossible position he's been in throughout his leadership.

Like all militaries in Latin America, the Venezuelan Army is full of reactionary brainworms (The Venezuelan Right/Opposition) also hates Guyana) and demands, they seem to be pretty loyal to Maduro considering how the 2019 military coup attempt failed to gain any support within the army saved by some high-ranking generals that ended up purged. Some people said Russia and Cuba had sent troops to help Maduro purge the army in 2018 - 2019 and that helped Maduro avoid a Bolivia 2019 coup scenario.