At first I was a little disappointed they put only one new song on the compilation. But now that I think of it that may actually mean somehing really, really good. Maybe they actually believe in "Infinity" and try to make it hit #1?
Hypothetically speaking, if "Infinity" does go #1 all the songs on the album
or at least the original versions of them 
would have been a #1 hit. The album wouldn't contain her #1's AND one additional bonus track, no, there would just be ALL of her 19 #1's even including her latest one, "Infinity", then.
At this point we haven't even heard the song. So this thought is nothing but a phantasm right now, plus chances aren't very high that the song – any of her songs – could really go #1 no matter how good it is. But the fact they might actually try for once would make me happy for her. If she, her team and her label believe in the song and release and push it the way a Mariah Carey single is worthy of and she FINALLY receives the care and priority she deserves, then that would just be too great to witness.