This is my personal understanding. But in the past, pathologists were very underpaid and compensation was not uniform, some getting a lot (if you were part of private lab) and some getting little. Few decades back, the government stopped issuing private lab licenses and some labs amalgamated into the public system. This mostly stopped the fee per specimen system and vast majority of pathologists became employees on salary. The effort was aimed at making compensation more uniform to confer to the public system ideal.
Because of this arrangement, in most places the only employer of pathologists are public hospitals/health authorities. These are publicly funded and have set a uniform compensation level for pathologists. Therefore if you want to work in a certain city, your choice of employer is limited. Since salary level is set by provincial standard, there is minimal negotiation room. Funding increases are negotiated by provincial medical societies rather than individual groups, therefore it is unlikely that a certain specialty will receive outsized increases relative to other specialties. Again, the impetus for large salary raise seems to be scandals that highlight human resource issues. For example, recently severe shortage of family doctors in BC exposed by the media prompted the government to increase funding to family doctors such that their compensation increased from ~250K to 385K.
There were a few major incidents over the years that highlighted the poor condition and pay of pathologists so gradually salary were increased after each scandal. A lot of pathologists here are IMG from South Africa, middle east, India, UK etc. Relative to those countries, the pay here is higher, so they seem to be content. For example, a pathologist from UK said his salary in UK was about 100K GBP, which is 130K USD, so his Canadian salary is relatively generous.
Since most pathologists have adopted to this "employee" mindset, a lot of effort is spent on arguing that there is too much work, rather than arguing for increasing value for work done. Most of the negotiation effort focuses on increasing FTEs so each pathologist gets less work, but less effort is spent on getting each pathologist paid more for their increased workload. For example, when a provincial medical society negotiates pathologist pay, they often compare to neighboring provinces. Since in each province the pay is very similar (370-420K), there is no argument for one province to give outsized pay increase relative to its neighbor.