The notion of expanding a portion of that existing section of TX-146 from a 4-lane street to a 6-lane street seems like a very modest, interim solution.
The next SH 146 project, from FM 518 to Dickinson Bayou, is slated to receive bids in May 2023. Estimated cost is $177.8 million. As the news article mentions, the widening will extend the freeway southward with an overpass at SH 96. But south of SH 96, it SH 146 becomes a 6-lane boulevard on the minimum needed right-of-way.
Looking at the schematic, there is right-of-way acquisition on the east side of SH146 from FM 518 to Bay Avenue (just south of SH 96), including displacements at Meadow. There is no right-of-way acquisition south of Bay Avenue.
As far as I know, this widening is the ultimate design and no further expansion is planned.