ITV News anchor Tom Bradby, a friend of the couple, claimed they were made aware of these developments during their recent trip to Canada.
The broadcaster, appearing on a news programme on his channel, said: "It had been made clear to them in their absence there was going to be a slimmed-down monarchy and they weren't really a part of it."
He said there had been a lot of arguments, adding: "Certainly the rest of the family find Harry and Meghan very difficult and, from Harry and Meghan's point of view, they're just being driven out as they see it."
But the Times reported that palace officials had stressed Harry and Meghan had always been central to the monarchy's plans, with one aide quoted as saying: "It is strongly disputed that the Sussexes are not at the centre of any future slimmed-down monarchy."
It came as a source revealed the Duke and Duchess of Sussex hope talks over their future roles in the royal family can be concluded "sooner rather than later”.
Harry and Meghan announced plans this week to step back as senior royals, become financially independent and split their time between the UK and North America.
The bombshell statement on Wednesday rocked the royal family and was said to have left the Queen and other senior royals "hurt".
Urgent meetings began on Friday after directions from the Queen and other senior royals.
It is understood the meetings were "progressing well" with the UK and Canadian governments consulted.
Speaking about the duke and duchess, the source said: "They, like everyone, are hopeful this can all be worked out, sooner rather than later.
"It is in everyone's interest for this to be figured out, and figured out quickly, but not at the expense of the outcome."
An opinion poll for the Daily Mail found 76 per cent of people said Harry and Meghan should sacrifice their Metropolitan Police protection after they "step back" from their senior royal roles, and 73 per cent said the same for taxpayer funded security measures.
A total of 60 per cent of people questioned said the Queen was treated badly, while in his first comments on the crisis, US president Donald Trump told Fox News' Laura Ingraham that it was "sad" for the monarch.
In a clip posted by Fox News on Friday Mr Trump, who has lavished praise on the Queen before, said: "I think it's sad. She is a great woman.
"She has never made a mistake. If you look she has had like a flawless time. I just have such respect for the Queen, I don't think this should be happening to her."
It is understood that a day-long series of meetings and phones calls were held by officials and royal aides trying to work up proposals for the Sussexes' future roles.
The timetable for finding workable solutions remains days rather than weeks.
In another development Harry and Meghan appeared to signal their intentions to forge ahead with building a life in Canada after Meghan returned to the country and reports indicated Harry will join her soon.
Harry and Meghan's Instagram account returned to publicising their appearances, with pictures released showing the couple during a private visit on Tuesday to the Hubb Community Kitchen in North Kensington, west London, run by a group of Grenfell supporting women whose recipes were featured in a cookbook backed by Meghan.
Speaking about Harry and Meghan's future public engagements, a source said "We're operating under business as usual, we've got a programme and a schedule."
Additional reporting by PA Media