Piers Morgan said he still does not believe the Duchess of Sussex as Good Morning Britain aired without him following his abrupt departure on Tuesday.
The presenter left the ITV morning show following a backlash against his incendiary comments about Meghan and her headline-making interview with Oprah Winfrey.
Broadcaster ITV announced in a brief statement late on Tuesday that Morgan was leaving the news programme.
On Wednesday morning, the journalist said on Twitter that he still does not believe what Meghan said to the US chat show host.
He tweeted: "On Monday, I said I didn't believe Meghan Markle in her Oprah interview. I've had time to reflect on this opinion, and I still don't. If you did, OK. Freedom of speech is a hill I'm happy to die on.
"Thanks for all the love, and hate. I'm off to spend more time with my opinions."
Susanna Reid said Good Morning Britain will be "very different" but "shows go on" as she addressed her co-host's exit and referred to his often divisive presence.
Opening Wednesday's programme, she said: "A number of people will know the news and many of you will not and will be surprised that Piers Morgan is not here this morning.
"Now, Piers and I have disagreed on many things and that dynamic was one of the things viewers loved about the programme.
"He is without doubt an outspoken, challenging, opinionated, disruptive broadcaster.
"He has many critics and he has many fans. You will know that I disagreed with him about Meghan's interview. He himself clarified his comments about her mental health on the show yesterday."
Reid said there are "many voices" on Good Morning Britain and "everyone has their say".
She added: "But now Piers has decided to leave the programme. Some of you may cheer and others may boo.
"He has been my presenting partner, Monday to Wednesday, for more than five years and during Brexit and the pandemic and other issues. He has been a voice for many of you and a voice that many of you have railed against.
"It is certainly going to be very different but shows go on and so on we go."
Ranvir Singh, Reid's co-presenter for the morning, responded: "Well said."
She described Morgan as a "big character" and said "many viewers will be absolutely gutted".
Singh called Morgan "Marmite" and acknowledged his role in Good Morning Britain's success.
On Tuesday morning, ITV chief executive Dame Carolyn McCall said the broadcaster's managing director of media and entertainment, Kevin Lygo, had been in discussion with Morgan in recent days regarding his coverage of the Harry and Meghan interview.
Speaking on a media call following the group's annual results, which were published on Tuesday, Dame Carolyn insisted Good Morning Britain is a "balanced show", saying: "ITV has many voices and we try and represent many voices every day. It's not about one opinion."
On Morgan's comments saying he did not believe the Duchess of Sussex, she said: "I completely believe what she (Meghan) said. It's important everyone does."
According to the Telegraph, Meghan has submitted a formal complaint to ITV following Morgan's comments.
The paper said a spokesman for the broadcaster "refused to deny" the reports.
ITV said it would not comment.
Ofcom also announced on Tuesday that it is investigating comments Morgan made about the interview.
The watchdog received more than 41,000 complaints about his remarks on Monday's Good Morning Britain.