I haven't seen an in-depth look at this information yet (outside of would it be good or bad for the Astros), but I do know that this could mean interleague play throughout the regular season.
6 divisions each with 5 teams could in theory make for a relatively straightforward and pretty well-balanced schedule. Each team could play its four intra-division rivals 18 times, nine home and nine away, for a total of seventy-two games. Then each team could play all the teams in three other divisions (the two other divisions in its own league plus one division from the other league) six times, three home and three away. That would make for 90 games (6 games times 15 teams). That's a total of 162 games. The interleague play would cover all teams on a three-year cycle, so the NL East teams would play the AL East teams one year, then the next year the NL East teams would play the AL Central teams, and the following year the NL East tams would play the AL West teams, and then the cycle would begin again. Besides being relatively fair and reasonably balanced, this cycle would have the nice effect of limiting the number of Mets/Yankees games, and similar interleague rivalry games, so that such contests regain their status as rare occurrences meriting great attention. I'm sure MLB won't go for that, because those intra-city (or intra-state) rivalry games are seen as an annual attendance and ratings boosters that the owners will not want to ration, but it still makes long-term sense to me.
As to having to play interleague games all season because of the uneven number of teams in each league, I wouldn't think that would be a big deal. With my suggested schedule above you would have to plan for 450 interleague games during the season, out of 2430 total games -- two or three of the fifteen series underway at any given time during the season would neeed to be of the interleague variety. I'm not sure why that would be a special problem.
One twist in this system I'd like to see but wil never happen is to have the inter-division wild card standings based just on the 84 games that would be comon for all teams in a particular league. So the Mets' record for interdivision wild card purposes would be based only the team's record in its thirty games vs. the NL Central, its thirty games vs. the NL West and its final six games against each of the four other members of the NL East. That would elimnate strength of schedule bias from competition for wild card spots. Of course that won't actually happen either,