I guess it is a valid fear. Unless a third party or a coalition forms government we are not likely to see Proportional Representation in any form. The reason is quite simple.
Under a Proportional Representation system it is quite likely that there could be an election with neither a con or a lib elected. It does largely depend on the methods used but if an electorate is given the freedom of understanding that they can for example no longer have to worry that a vote for the Cons is the only way to defeat the Libs or that a vote for the Libs is the only way to defeat the Cons they are going to be more likely to support their first choice instead of a supposed least worst of two choices.
Now this particular election is going to be interesting as i see a realistic chance for both the PANB and even the NDP to gain seats in this election. I also believe that it is possible for the Green party to get a seat or two.
The truth it is a realistic option for this election to produce a minority government and that worries both major parties because it has been so long since they were faced with a minority govt that they would not be sure how to proceed.
A minority govt would at this time be the best option for this province barring a flat out PANB win.
But on the base issue of Proportional Representation if the two main parties had to go up in this election facing a ranking system and the other three parties each had 55 candidates on the ballot they know that it would be highly unlikely that they would have more then two or three seats each.
That fear and that knowledge is why unless a third party ever carries the balance of power or holds power it is unlikely that they will ever face a proportional representational ballot. Especially one of a ranking system.
Most especially though this election would annihilate both parties beyond the point of recognition and that is why they would never countenance facing a ranking system of ballots in a proportional representation vote if the Libs and Cons have any say in the matter.