His summary of the bill was rather incorrect, so the better question would be whether he's changed his criticism of it when exposed to new information.
I think his criticism of the bill did evolve over time, at least from the two points of reference that I have, which is his initial YouTube video to his testimony as an expert witness in the senate hearing.
I watched part of the senate hearing last night and his main point was that bill C-16, which added gender identity and expression to both the list of prohibited grounds of discriminations and the criminal code, but it didn't bother define what exactly gender expression and gender identity were. The claim he made is that the Federal DoJ thus will use the Human Rights Tribunals for these definitions, I have not seen this claim disputed, and I believe there are several examples historically that illustrate this is indeed the case. Upon consulting the Ontario Human Rights Code, you will find the following:
Gender identity is each person’s internal and individual experience of gender. It is their sense of being a woman, a man, both, neither, or anywhere along the gender spectrum. A person’s gender identity may be the same as or different from their birth-assigned sex. Gender identity is fundamentally different from a person’s sexual orientation.
Gender expression is how a person publicly presents their gender. This can include behaviour and outward appearance such as dress, hair, make-up, body language and voice. A person’s chosen name and pronoun are also common ways of expressing gender.
Discrimination happens when a person experiences negative treatment or impact, intentional or not, because of their gender identity or gender expression. It can be direct and obvious or subtle and hidden, but harmful just the same. It can also happen on a bigger systemic level such as organizational rules or policies that look neutral but end up excluding trans people. Friends, family or others who face discrimination because of their association with a trans person are also protected.
First of all, I find the definition of Gender Identity to be completely nonsensical. That aside, it is the case that whether intentional or not, if someone experiences
negative impact because of their
gender identity, this is now part of the criminal code in Canada. One form of negative impact is being unintentionally mis-gendered.
In fact, the Ontario Human Rights commission have an entire section on whether or not it is discrimination to not address people by their pronoun, which the conclusion is likely if done in social areas covered by the code, and cite an example where the Tribunal found the police guilty due to mis-gendering, however it was not clear whether or not this was intentional. So yeah, his interpretation seems to be more or less correct as far as I can tell. The controversial bit is whether you have to specifically use some of the non-traditional pronouns, it is simply not clear if you have to do that. The Ontario Human Rights commission says:
The law is otherwise unsettled as to whether someone can insist on any one gender-neutral pronoun in particular.
Gender-neutral pronouns may not be well known. Some people may not know how to determine what pronoun to use. Others may feel uncomfortable using gender-neutral pronouns. Generally, when in doubt, ask a person how they wish to be addressed. Use “they” if you don’t know which pronoun is preferred.[2] Simply referring to the person by their chosen name is always a respectful approach.
So, it seems like the only way to be safe would be to use them. You should ask and then use whatever they tell you. If you don't know, you can use 'they', but only if you don't know. It's easy to get lost in the details. I generally agree that I find these laws, however well intentioned, to be dangerous and convoluted.