Libs didn't. C24 did. Stay on C24 related revocations was halted and thus c6 was brought and pushed forward, but Senate........
Yes the liberals did. C-24 gave the minister (or his delegate) the power to revoke citizenship if they are convinced that fraud happened. It is, however, the ministers decision if and how he uses that right. It seems, in fact, that the Liberal government put additional effort into using these provisions. That was their decision. Just like a local politician can decide to concentrate the police force on catching jaywalkers instead of helping kids on their way to school, the Minister can decide to concentrate the IRCC workforce on using these C-24 provisions instead of speeding up other processes.
Independent of the question if that is a good choice or not and what the appropriate balance is, it is a choice that this, the liberal, government made. So you can't say that the Libs aren't responsible for this. In fact, on top of that, they even refused to abolish the C-24 provisions regarding no appeals process when opposition MPs suggested just that in the committee of the HoC. The only reason why the Senate had to get involved like this is because the Liberals refused to change a part of the law that all experts agreed on was not within the limits of due process. Their ignorance is responsible for this.
This bill has many good parts, but the Libs are also responsible for the bad ones.