I completely agree in a general sense. Anything they call a "collection" really needs to have all the content, or as much as possible. On the other hand, I should point out that as far as in-game content goes, the Digital Deluxe Edition only adds some (admittedly take-it-or-leave-it) armor and weapons.
Even so, this collection still leaves out things that really should just be thrown in for free at this point, such as the Firepower Pack (Phalanx Pistol, Geth Shotgun, and Mattock assault rifle), the Aegis Armor pack, the Equalizer Pack, and the two Alternate Appearance packs.
Side note: When the PS3 edition was released, I think it came with this same stuff. I think they're trying to mimic that version on PC without actually having to create a new SKU.
I agree with your point on Digital Deluxe. there is no vital and exclusive item or mission included. However, as a 'collection', personally I just prefer more even if its price is higher. Actually i think ppl who buy this are going for the biopoints, i.e., they should own me2 already.
I totally agree with your opinion on Firepower pack. It is quite disappointing that it is not included. But after reading your theory on SKU in the sidenote, i reckon that is a very promising explanation.
Lastly, I think the keys for dlcs are actually redeem code for biopints rather than a specific dlc activation, as the current existing items looks like redeem code on bioware websites. If so, we can use it to buy citadel and other dlcs. But ppl need to confirm this.
You can use the Bioware points for anything. No DLC is "included" here, the one's listed are just indicative of what you could buy. Most people I'd guess buying the pack will ignore the ME2 key they already have and use the points to buy ME3 DLC. Ignore the ME2 key, and $25 for Bioware points you can use to buy $30 of ME3 DLC is still the best deal you're going to get on them.