What I mean is when Champions #1 was re-solicited last month it was as "CHAMPIONS #1 (of 5)" which led everyone to believe Marvel turned the book into a mini series. You can see what I mean by checking October's solicit for the series
here. And at one time it said the same thing on the PREVIEWS World catalog website (as I've stated before they recently changed it back to Champions #1 and dropped "(of 5)").
As for Marvel's subscription site I believe that works the same as a magazine subscription. Meaning that your only paying for one year's worth of that series issues and not the entire run of said series.
This also explains why it says your subscription for Miles Morales: Spider-Man ends with issue #26. If you started your yearly subscription around issue #14, then issue #26 is the end date and you will have to re-new your subscription for another year.
...P.S. I found this on eBay so I can't be too sure, but this might actually be Peach Momoko's 1:50 variant for Champions #1. But like the asterisk states this may be subject to change for the final cover.