The act or practice of conspicuously displaying one's awareness of and attentiveness to political issues, matters of social and racial justice, etc., especially instead of taking effective action. [1]
And from the person who coined the term:
British journalist James Bartholomew claims to have originated the modern usage of the term "virtue signalling," in a 2015 Spectator article. His 2015 formulation described virtue signalling as empty boasting.
"No one actually has to do anything. Virtue comes from mere words or even from silently held beliefs. There was a time in the distant past when people thought you could only be virtuous by doing things...[that] involve effort and self-sacrifice." [2]
Fair criticism if you ignore the coiner of the term and focus only on the first definition I supplied.
I thought it was obvious that talking about moving to a platform is very different from actually making the move. The author has presumably moved, which is taking effective action and can be contrasted with people who are saying they are going to move but haven't done anything about it.
You should also note that the coiner of the term disagrees with you:
No one actually has to do anything. Virtue comes from mere words
I don't think it's fair to call it virtue signaling when someone took effective action. Does that clarify enough?
tl;dr: "I don't like Elon Musk either!"
Nothing but virtue signalling.