Yep I would support this. Not only tougher but require more players. Why not have multiple world bosses on each planet?
Some could be considered mini-Ops (caves with short run of mobs to kill, puzzle to master then followed by boss) .. groups could team up to clear several bosses.
Large groups would be awesome as long as performance on SWTOR servers could handle it.
Could have quests or rewards or weeklys as well to encourage grouping for these further along with relevant gear or rare item drops. Could have rare sets to collect by downing multiple different bosses across planets.
Some could have unique challenges to master. Speed kills, immune to XX, need to kite to another location a distance away to kill, boss only spawns after killing another world boss or side quest, do with only xx players .. sure there is more possibilities.
Make them tough, make them clever
Make it worthwhile...