I must agree with the previous posters; this doesn't qualify as genderswap.
Unless you consider going from male to neuter a genderswap?
Yes, one can argue that magic wands are phallic symbols, and a number of the previous posters make that very argument...
But...
He doesn't seem to be having... inappropriate reactions... to the magical girl's outfit, or being carried tucked between her breasts; no mental or verbal comments or observations that she would find offensive have occurred.
From that perspective, he is a true magical girl fan, because he's completely oblivious to just how much fan service is built into the very concept.
The ecchi tag, on the other hand... that's most appropriate, indeed!
Enough so, that I quite understand the true magical girl fans not liking this at all.
Because it's definitely parodying the extent of fan service generally provided by magical girls.
The girl herself... yeah.
She actually is a good candidate for being a magical girl
At heart, she really does care for others, even when they've treated her like dirt.
With the villagers, she made no bones about having every reason to hate them, but she still didn't want to leave them to be killed by monsters.
And I quite understand her finding the lines she has to recite, and the outfit she transforms into, most embarrassing.
Of course, it's that embarrassment factor that makes this appealing to some.