I haven't actually watched it, but is still the old quantity/quality boost even on positive map mods? Because those downsides on PoE1 maps did come with an upside in that regard, they were purely negative.
From the brief look at rolling maps they showed Item quantity, pack size, and rarity as prefix modifiers that can roll independently of each other and are no longer tied to the negative suffixes. That means that you could *theoretically* have a 3 prefix only map roll that is all upside and no downside.