I thought it was a remix but then saw it was just the date in 2014 where the original was posted. Still the only Mirai theme song that was never played live and while I personally think it just isn't a good live song anyway, maybe it would still be nice and appropriate for this anniversary Mirai to feature the song for the first time.
Loosely on that topic (since I am bored), here is how I would rank all the Mirai theme songs from "not as good" (didn't wanna say worst xd)" to "best", maybe somebody else is interested in posting their ranking too (if you are just as bored^^):
9) Next Nest (2014) -> Not my style of music and just not a live song, still not bad at all
8) Hatsune Tenchikaibyaku Shinwa (2021) -> Doesn't feel so appropriate for an event, nothing too special imo
7) Suna no Wakusei (2017) -> Always rubbed me the wrong way that the song isn't really "happy" considering it was the big 10th anniversary, still a cool song
6) Future Eve (2022) -> First impressions at least, not the biggest fan of the producer, but this song seems good, at least
5) Hand in Hand (2015) -> Used to love this song to death but then they just played it tooooo much so I kinda got sick of it a bit. Still awesone song. All of them are, from this point
4) 39 Music (2016) -> So perfect for a live concert. Just the kinda Miku song I love
3) Bless Your Breath (2019) -> Didn't love the song so much before the concert but live...so amazing. Also my (so far) last Mirai memories...the feelings! Just so perfect live
2) Aisarenakutemo Kimi ga Iru (2020) -> Wished I heard it live, sooo much feeling in this song, THIS would have been perfect for Miku's 10th. Hope I can still experience it live. Just would also deserve audience cheerings for the performance! Just an amazing song
1) Greenlight Serenade (2018) -> Still untopped imo. The enegery, the passion, the love from Miku. Brought to a whole other level when experienced live. I hope to return to Mirai and experience it. Just perfection.
Hmm lol I put so much time in this, I should have just come back from my YouTube hiatus and made a new toplist for my YT chnannel xd Oh well...