Does that stretch of highway need some type of relief? Yes, absolutely. Is it going to worsen things during the construction? Most definitely. Can your town persuade TxDot to make the transition on your community as painless as possible? Depends on who they hire to negotiate with TxDot.
The environment will have to suffer, but TxDot will take the necessary measures to protect your water sources. I expect that aspect to be limited since most cities pipe in water.
It's only a matter of time before the surrounding communities like Argyle and Bartonville are full blown. By full blown, I mean as large as Highland Village. The IH35 corridor will be surrounded by business and apartments. Sleepy towns that are 25 minutes from Dallas or Fort Worth will be no more in 10 years.