Lotto were entering minimal number riders at WT races they didn't want to be at in order to target smaller races for months. IPT just basically thought it couldn't happen to them until it was too late and it already had done. If you look at how the teams who were under pressure acted, IPT essentially stuck their fingers in their ears expecting their riders to come good until it was already a crisis, and then threw money at the problem because they had too much of a deficit, and because most of the other teams who were worried about it had already taken action (EF, BikeExchange, Lotto) they were left behind (Movistar did also take action very late in the day, but in the end a strong finish to the season meant they probably needn't have done so). It's not like they didn't have the same opportunity to select their rosters and target those other races. The UCI set out a points system and while that points system is pretty stupid, other teams figured out how to game it and IPT were too slow and had too much of their budget wrapped up in riders who were signed more for their name value and what they had achieved than what they would achieve. That's not necessarily even a criticism, they may well have known that when they signed them - but they needed to understand the vagaries of the points system, and they just gave the impression that, like Movistar, they just kind of figured they'd be OK and have nothing to worry about until right near the end of the three year period when they suddenly needed to take urgent action - and they were in a much worse position than Movistar in terms of both their potential points scorers and the points they had banked when they finally lurched into action.
I think the fact that the ranking is over a 3-year period where riders' ability to prepare is going to be so badly affected by coronavirus cancellations and lockdown restrictions is a better case to make, as if IPT had a disproportionate number of riders based out of countries or regions that were under tighter lockdown restrictions for longer, or could point to races on their calendar which were cancelled or downgraded on short notice, or were forced to withdraw either riders or the whole team from races they had planned for Covid reasons, or could contend that points were lost by race shortenings or cancellations (e.g. the BinckBank Tour having all its Dutch stages cancelled), that would definitely be a legit grievance and is the angle I thought would be the basis of a legal objection for whoever got relegated in all honesty.