Will the cancellation of the hotel reservation be cancelled by the embassy?

Which country are you talking about? Some countries care, while others don't. If the hotel you originally booked cancels your reservation during your visa application, the embassy will sometimes find out. For example, Schengen countries in Europe are sensitive to this, and some embassies will call you to ask why you canceled your previous hotel reservation. If you can't give a reasonable explanation, you may have passed, but your visa will be refused or revoked. However, if you want to cancel your original hotel trip after you have applied for a visa and have your passport in your hand, basically no one will take care of you and no one will cancel your visa.