The knock against Dolmar/Makita in 50cc range, has been the extra weight and I'm sure that costs them in sales. I don't think there is any denying that weight/form factor has played a big part in Husky's success in the 50cc class.
Husky appears to be taking a gamble on this saw by giving up the weight advantage, especially now that Stihl will finally move into the low weight lead with a 10.8 lb 50cc saw. I can only assume Husky's confidence in the new 550xp MKII means the new saw is outstanding in so many ways, that they believe buyers will be prepared to overlook the extra weight.
For me, this new saw, being closer to the weight of a 562xp, will either be so good that I won't need my 562xp anymore, or it will fall short of being able to replace the 562 and I'll still want something lighter to better compliment. I would be more confident in their decision to forego their weight advantage, if they had managed to make this new 11.69 lbs saw come in at 54cc/55cc.
Time will tell.