I heard someone mention there's about a year's worth of YGO to run before they run out. A common theory is that OP will be dropped after chapter 100 or so, for monthly tankos, like DBZ.
So I got thinking: Four of the six series featured monthly are over (SK, YYH, YGO, and HnG). There's going to be a clear and immediate need to replace them when they run out. That's aside from any "board room decisions" to kill off a series.
What do you see happening? What serieses can you see plugged in there? I can't see them just allocating the space to the remaining series, cos in 3 or 4 years, you'd just have 8 chapters of OP and 8 of Naruto every month.
Personally, I'd like to see them stick a chapter of Bo-bobo in each month. One chapter's enough silliness at one time IMO.
I could see Eyeshield 21 succeeding in a monthly format, because Americans will connect better with football than Go (of course, assuming people aren't drawn to the foreignness of it). One of their more popular non-ASJ series, like Bleach, could perhaps be used to drag a tanko-buying fandom into also buying the magazine.
But I'm not certain they'd want to put a "running" series into ASJ, as it would upset tanko buyers with a fixed schedule. I could see them using the opportunity to start off a newly licensed series in ASJ, and then have the tanko releases calibrated to the ASJ publication rate. But what would you expect there?
Another alternative might be to run one or two "short series", which ran between 20 and 50 chapters, with everyone knowing it's only gonna be there for a year or two.