If an application is already in progress, it most likely will not be cancelled, unless the application does not meet the program requirements and in that case it will be refused.
Also, to cancel any application submitted with IRCC, a law has to be passed either in the Parliament or the Provincial legislature, which will be done after much deliberation and is always controversial. Nothing of this nature has even been contemplated, leave along being presented as bill.
The reason why I say that applications for which the processing has commenced will not be cancelled is because of a legal doctrine called "legitimate expectation." Simply put it means that once an application is submitted and the processing commenced, there is an expectation that a decision on it will be released.
However, since"legitimate expectation" is not a statutory rule, instead it is a common law doctrine, it can be overturned by a law passed by the legislature. However, given that significant resources, funds and time has already been invested in processing applications, cancelling them just does not make sense, and legislatures usually do not over turn any application for which processing has already commenced.
This was reflected in 2012, when Canadian Parliament under the Conservative government cancelled all pending PR application, except the ones for which the processing had commenced, and then brought express entry, which has been a success since then.
Since Provinces deal with much smaller volume of applications, they can frame more absurd laws, but unless a bill is tabled before the Parliament or the Provincial legislature, it will then have to be sent to a committee for deliberation and debate, it makes no sense to discuss it