Wilson-Raybould attended last week, and it's yet to be seen if she'll be present today in advance of her appearance.
"It's important that people get an opportunity to testify, or share their point of view, at committee", Trudeau told reporters as he headed in to the weekly Liberal cabinet meeting.
His comments could also indicate the government has determined there are aspects of the matter that are not covered by solicitor-client privilege and which she should feel free to speak about, and more information is expected shortly.
It has been almost three weeks since the allegation first surfaced that Trudeau's office pressured Wilson-Raybould last fall to negotiate a remediation agreement with SNC-Lavalin, rather than pursue a criminal prosecution for corruption and bribery related to government contracts in Libya.
Wilson-Raybould was shuffled to veterans affairs from justice in mid-January, and then resigned from cabinet a few days after the allegations were made public.
"I mention this simply to alert the committee to the fact that the order-in-council leaves in place whatever restraints there are on my ability to speak freely about matters that occurred after I left the post of attorney general", she wrote.
"The approach that we are taking in both the ethics committee and the justice committee is looking into the issue of whether or not the AG underwent pressure or inappropriate pressure and she will be able to speak fully", he said.
Wilson-Raybould said that during a September 17 meeting with Trudeau and Michael Wernick, the government's top public servant, she was warned that if SNC-Lavalin is not given a remediation agreement-a type of plea bargain that would allow the company to avoid a criminal conviction-it would mean the loss of many jobs and SNC-Lavalin moving out of Montreal.
Conservative Leader Andrew Scheer, speaking immediately after Wilson-Raybould's testimony finished, said Trudeau had lost the moral authority to govern the country and should resign.
The former minister requested 30 minutes for an opening statement which the committee has accepted.
The order also waives "solicitor-client privilege and any other relevant duty of confidentiality to the Government of Canada" with respect to Wilson-Raybould's discussions with government officials "respecting the prosecution" of SNC-Lavalin while she was justice minister.
Gerald Butts, Trudeau's closet adviser, resigned last week but denied that he or anyone else pressured Wilson-Raybould. Wernick said he was informing the minister of "context" surrounding her decision on the company but insisted it was not inappropriate pressure.
Citing her chief of staff's account of the exchange, Wilson-Raybould quoted Butts as saying: "There is no solution here that does not involve some interference".
Some of her former cabinet colleagues seemed relieved Tuesday that whatever complaint Wilson-Raybould may have about the way the SNC-Lavalin matter was handled, it will finally be out in the open after weeks of shadow boxing with anonymous sources.
It has pushed unsuccessfully for a remediation agreement, and the Trudeau government has been plunged into controversy over accusations it improperly pressured the former attorney general to make an agreement happen.
The waiver given to Wilson-Raybould to speak about her time as attorney general also applies to others in government with whom she spoke about the SNC-Lavalin prosecution.
Her chief of staff, Jessica Prince, was eventually summoned to an urgent December 18 meeting with Trudeau's chief of staff, Katie Telford, and his then principal secretary, Butts.
So far, the Liberal majority on the justice committee has balked at calling staffers as witnesses, but it could reconsider after hearing from Wilson-Raybould.