I don't think match-up changes in this series by Dallas should mean much regarding what next year will look like. Dangerfield trying to guard Gray is a unique unusual scenario. Gray is pretty tall and strong and with her fade away can often score with a defender right in front of her, that is her own height, much less 6 inches shorter.
It was an impossible match-up for Crystal, but the good news for her is not many point guards can do what Gray does.. Dangerfield may be a marginal long term prospect to start at the point, but can probably carve out a long WNBA career as a reliable backup, and until they get a better option I suspect she could still be in the mix for next year,
Size in the back-court is also an issue for Dallas because of their shooting guard. Arike has point guard size but obviously is more of a shooting guard in style. Combing her with a smaller point guard means there will be some defensive match-up problems.
Look at Vegas for comparison. Plum is also more point guard size but shooting guard in style. But she pairs very well with Gray because Gray is big enough to guard the SG's and Plum can guard the PG's. They reverse positions on the defensive end and it works.