He's using the last of the definitions you linked to: "one that is generally unmanly." No homophobia anywhere to be seen.
I also grew up using pansy as in weakling, as in like the flower. Gay men can be pansies or not. Straight men can be pansies or not. Sometimes I am a pansy. Sometimes I am not.
There is a connection to offensive meanings even if it's not strictly a slur. It's the wrong word here anyway--really the opposite of what I would take as the intended meaning. The behavior being argued here certainly isn't weak; those arguing against it are saying that it's overly aggressive.
Sometimes being overly aggressive is exactly what marks you as a weakling.
"There is a connection to offensive meanings even if it's not strictly a slur."
Honi soit qui mal y pense.
If you really felt that strongly about it I don't think you'd create a new account just to say so.