You are completely wrong, please stop posting this bad info.
There is no need to get divorced from first wife, as if he's lived together 12 months with new partner then he is now legally common-law for immigration purposes even though he's legally married on paper. All that's required is that he's physically separated and no longer in a relationship from his first wife. This is perfectly fine.
https://www.canada.ca/content/dam/ircc/migration/ircc/english/resources/manuals/op/op02-eng.pdf
5.38. What happens if the common-law partner (principal applicant) is married to another person?
Persons who are married to third parties may be considered common-law partners provided their marriage has broken down and they have lived separate and apart from the spouse for long enough to establish a common-law relationship – at least one year. In this case they must have cohabited in a conjugal relationship with the common-law partner for at least one year. Cohabitation with a common-law partner cannot be considered to have started until a physical separation from the spouse has occurred.
a) Mutual commitment to a shared life to the exclusion of all other conjugal relationships
A conjugal relationship is characterized by mutual commitment, exclusivity, and interdependence and therefore cannot exist among more than two people simultaneously. The word "conjugal" includes the requirement of monogamy and, therefore, an individual cannot be in more than one conjugal relationship at one time. For example,
a person cannot have a conjugal relationship with a legally married spouse and another person at the same time. Nor can a person have a conjugal relationship with two unmarried partners at the same time. These would be polygamous-like relationships and cannot be considered conjugal.
Persons who are married to third parties may be considered common-law partners provided
their marriage has broken down and they have lived separate and apart from the spouse for long enough to establish a common-law relationship – at least one year. In this case they must have cohabited in a conjugal relationship with the common-law partner for at least one year. Cohabitation with a common-law partner cannot be considered to have started until a physical separation from the spouse has occurred. A common-law relationship cannot be legally established if one or both parties continue their marital relationships.
Officers must be satisfied that a principal applicant is separated from and no longer cohabits with a legal spouse. This evidence may be in the form of a signed formal declaration that the marriage has ended and that the person has entered into a common-law relationship. An officer may require that the person produce
other written evidence of a formal separation or of a breakdown of the marriage. Acceptable documents include
a separation agreement, a court order in respect of custody of children identifying the fact of the marriage breakdown, documents removing the legally married spouse(s) from insurance policies or will as beneficiaries (a "change of beneficiary" form).
Not living together is just one of the condition. A proof of separation is needed as well.
According to what he has stated, he did not fulfill condition of the formal separation. Living apart is not enough. So if his current wife is not cooperative he has to go through the legal way to obtain the formal separation confirmation. An any time before that would not be counted into common law with his
new partner.