Not surprising, all the ME games have been released in the early part of the year. ME 1 & 2 were released in January and ME 3 in March, so Q1 2017 is very likely
This is not true at all. Mass Effect 1 released on November 16, 2007 for the Xbox 360. You must be confusing it's original release with the PC port, which came on March 10, 2008. Otherwise, ME2 and ME3 all have shared the same pattern of Q1 releases.
BioWare better blow us away at E3, otherwise I'm really concerned about this game. It has had a far longer development cycle than any other BioWare game. Yet, we know next to nothing about it. If we don't receive substantial information about MEA at E3, Comic Con, or N7, that makes me worry a lot. It means the product isn't in a good enough condition to show to the public and it means development is not going well at all.
While delays can sometimes be a positive, they often are a negative. DAI was delayed and it was still buggy at launch. ACU was delayed and it was still a disaster. BAK was delayed and it was clearly an absolute mess. TW3 was delayed and while it was playable, it wasn't optimized well at release. There are very few examples of games that actually seemed to really benefit from a delay. It's far more likely MEA will have issues at launch regardless of it being pushed back a couple months.