I don't think the mini-suites are much of a gamble. Or at least, in my head, I'm imagining those mini-suites as the smaller and cheaper alternative for the average fan who wants a suite for a game here and there.
I know a lot of people who want to get a suite for their birthday but it's just way too damn expensive, and most times you don't need all that room. I think a suite for 8-10 people max might catch on much better with the average fans and smaller businesses.
I know they've done much better selling suites/corporate plans so they must be anticipating the demand in a year or two for more suites, which is a good sign.