Iraq is in the playoff. By similar logic to your point below, you can't just arbitrarily decide that two of the teams don't need to play of their playoff match and both would automatically qualify without having to play. That also ignores the problem that would persist, that Iraq might not be able to play in the World Cup if they advance for the same reasons Iran can't. It would be unfair to all the other nations in the format who are required to play their playoff match for 2 of the teams to not have to. Why should Iraq or Bolivia / Suriname get to bypass the match that they are supposed to play in to get into the tournament?
By that same logic, the number of playoff spots and playoff matches "for each confederation was established from the start and shouldn't change". It's important to note that the number of spots for each confederation in this expanded field were not allocated equally or fairly between Feds. Just looking at the UEFA WCQ format compared to the standard format that we have become accustomed to, this is completely different. So I get your wanting to keep the spots allocated to each Fed the same, in a normal situation that makes sense, but here it's not so simple, with the war raging and with there not being a clear or a simple solution to the problem.