I definitely think it is possible. I agree at the Jeff Goff comparison. He is resembling a 1st rd QB a lot more than he did year one with Fisher. In fact I think a lot of folks felt like besides Wentz we had gotten the next best qb in the draft. I think Dak is not as good as he was in 2016, but not as bad as he is now either. In 2016 I think he was put in the perfect storm. A solid, fully healthy top tier OL with a road grader mentality that opened up massive running game holes and gave him all day to throw. He had a solid TE that was reliable to be where he was supposed to, and could only add to the blocking assignments for him and or Zeke. Dez was still a threat even if he was starting to decline, he drew coverage, and Beasley and crew picked up a lot of the benefit.
Now, after the OL is nicked up, and also inexperienced he is either under too much pressure from the left guard spot and up the middle, or when he does have time he thinks like he is standing behind the 2016 OL and has all day to look down field. He's still missing Witten and his reliability to be a dump off, but with Cooper he is adding the Dez threat back to the equation, only he will have more ability to separate and get open then Dez did, but just needs some time to build up chemistry. That all said his accuracy is still an issue, and I'm sure there are some mechanics involved in that as well as his mental blocks he's developed on finding open reads and or taking too much time to look the wrong way and miss the open read. Not to mention over throwing or coming up short on passes.
For 700K you're not going to find a better QB than what we have now for next year. If a new coach can't get him to play better we will be drafting one I'm sure in 2020. If he does play to expectations, I'm sure he'll get tagged for a year to make sure before a long term deal is inked. As questionable as we all think the front office is at times, I think if anything they've proven to be more financially frugal in recent years. I doubt they'll extend him to some $100M long term deal before they feel there is evidence to justify it.