The political leverage of this issue will not be about electoral reform, per se. IMHO.
However, it will usefully serve as one of the more flagrant examples of Liberal lies and broken promises to be cited and re-cited repeatedly. So an important part of the re-branding of the Trudeau Gov't prior to the next election, along with the betrayals over marijuana, pipelines, C-51, etc.
Of course, having won on the "Be grateful I am not Stephen Harper!" bandwagon in 2015, one can only reasonably expect Trudeau to run on a "Be really grateful I am not Donald Trump" platform in 2019. And it may well work.
I can respect a party to some degree if in breaking a promise they account and explain reasons why things have changed or what they learned. But to just ignore and move on from them is another thing. There is no humility.