Yes. But as the referee you aren't in control of those other restarts."The whistle is needed to:
restart play after it has been stopped for a:
•caution or sending-off
•injury
•substitution"
"The whistle is NOT needed to:
• restart play from:
•most free kicks, and a goal kick, corner kick, throw-in or dropped ball"
I originally thought the same as you James, but do you blow to restart from a throw after a sub or injury? Yes you do. Why is drop ball different? It says whistle is not needed for throw, but you do?
I believe the law is saying 'unless there are other circumstances' a whistle is not required.
I just can't ever imagine ever whistling before or during a dropped ball, as despite the guidance, and differences in interpretation, it just does not feel necessary because I will be there controlling a restart. A throw, corner etc. etc. the player has the ball so needs some signal to start. Whereas in a dropped ball scenario my dropping of the ball is that signal.
In the very next sentence the guidance talks about not over using the whistle.
Also note its guidance here not law so whilst we have a difference of opinion neither of us is wrong I don't suspect.