The thing here is that Manchester United fans actually seem remarkably placid about this whole situation.
Contrast this for instance with the attitude of the Newcastle United fans during that 2020-2021 period where Newcastle United's takeover by PIF was being blocked by the Premier League. In response, Newcastle United's fans organised multiple pressure movements, including a fan-funded legal challenge to the Premier League for alleged anti-competitive behaviour, mass email campaigns to their MPs, sustained harassment of the Premier League's sponsors, in-person protests at the Premier League headquarters in London. All of which were actually pretty successful towards putting pressure on the Premier League to eventually approve their takeover.
Point being, Elliot Group would likely be highly sensitive to similar pressure tactics from fans, yet I can't see any such attempts being made by fans to utilise their potential influence.