There would be a certain irony to that - so CAATSA kept Egypt from acquiring Su-35s, but possibly at the price of placing the very same airframes into Iranian hands. I mean, you have to wonder where they'd be liable to do less damage to US interests...
CAATSA is never about the buyer, the intent is simply to counter Russia at virtually any cost. As you can see from the above example, this goal may potentially be pursued to the point of damaging the interests of an actual US ally (Egypt) to the benefit of an adversary (Iran). Algeria (unlike Iran) just has enough economic ties to the US that there is leverage to easily enforce CAATSA, and as it's not a close partner (like Egypt is), there will be even less hesitation to do so.
