Bugs aside:
Mass Effect 3 MP was essentially endless hours of wave defense, with one of four objectives types randomly generated on waves 3, 6, and 10.
Dragon Age: Inquisition MP is essentially endless hours of dungeon drawling, with one of two objective types randomly generated on zones 2 and 4.
ME3 MP as of final MP DLC : 67 different characters in 6 different classes (61 characters if you take away the base human characters have identical male and female variants), 62 distinctively different weapons in 4 rarities in 5 weapon categories, 10 maps, 4 difficulty levels, 4 enemy factions.
DAMP as of no official MP DLC (minor MP content added): 12 different characters in 3 classes, 25(?) levels of 12 different weapon types (each weapon of a base class type handles largely the same, with minute differences, regardless of level) with 3 rarities in 4 weapon categories, 3 maps, 3 difficulty levels, 3 enemy factions.
Now, ME3 MP did only start off with 12 characters (which was honestly 6 characters, since it was a male and female variant of each class). There were 3 enemy factions, 3 difficulty levels, and 5? maps. I do not know how many weapons were available before DLC, but otherwise that appears really similar to Inquisition MP's numbers. If Bioware repeats a similar pattern, we would see somewhere around 10+ characters in each class (which would be half the total of ME3 MP), at least 3-5 new maps, 1 new factions (bets on that it will be Darkspawn), and 1 new difficulty level.
I am not sure how they will handle weapons, as ME3 MP thrived on weapon diversity, where each different weapon handled in a unique way for the most part and really played a major role in your character build, whereas Inquisition seems to only vary in the basic weapon type, damage, and whether it has a masterwork modifier (like "On Hit: 2% Chance To Do x Ability"). In other words, no matter what 2-handed warrior weapons get released, a greatsword will be an AoE 2-handed weapon and a hammer will be a single-target 2-handed weapon.