I dont think the mining supply redistribution is aimed at improving long term sustainability. In my opinion it is more possible that Ryan Taylor and other DCG insiders are using this and promises of "DASH Platform (Evolution rebrand) soon" as an attempt to pump the price once more before selling their coins and quitting (to avoid being fired for years of poor performance after Evan Duffield left).

If you follow the DASH forums, it appears that community members have given up competing with Monero (privacy by default) long ago.  Currently the DASH community worried about other opt in (and rarely used) privacy projects like Zcash passing them in the MC rankings.  Decred with technically superior governance model will likely pass DASH in the MC rankings at some point.  As blockchain users become better educated, marketing based on feature copying/re-branding from DASH loses its appeal.  The pace of the DASH network collapse will only increase if the recent DCG proposal to reallocate rewards away from miners is successful.