I don't think it was the plan, but they got worried by the atmosphere at Anfield in the last couple of games.
If it's true that FSG want a coach and not a manager, then replacing Slot may not be the solution. Last summer they made a big deal about chasing Isak, which they did all summer. Even when they bought an alternative (Ekitike) they still paid a large sum for Isak.
Meanwhile, they were pursuing a defender. They let Quansah go while pursuing Guéhi. They assumed Palace would fold and didn't seem to have a back-up plan. As a result they unbalanced the squad. The extra striker was useful as Isak got injured (probably because he was unfit due to his strike at Saudi Sportswashing Machine), but being CB short put more onus on their other CBs, one of whom is ageing and another who wants out.
The people who came up with this transfer strategy are still at the club, in fact they were the ones who decided that the coach was the one needing replacement rather than consider their role in the poor season.