What were those shoes with the actual metal coil springs? Spiro, Spira? Now, I don't remember the exact story. Did the IAAF weigh in and say no dice? Well, they'd be allowed now, wouldn't they? Something tells me that a well-founded outfit coming up with a Spring - it's specifically called a spring in the linked documents - is what made it OK.
So, I don't really think ASICS, et al were caught sleeping and unaware then scrambled to catch up so much as they never worked on Spring technology in the first place since they thought it was not allowed. I mean, why wasn't Brooks or whoever working on this 8 years earlier - or 28 years earlier? No one was even trying this angle and they all thought no one else would - you know, because it was against IAAF rules and look at what happened to Spira or whoever that was. Then when someone heavily sponsoring the federations and events does it (were there well-placed bribes? I believe Coe is on their payroll and has been for decades so he owes them big. In that case there doesn't need to be actual 'bribes') it's considered OK.
The other guys may not have immediately tried to do it thinking it was still not OK. We're they waiting for a ruling or sanction or something? It just doesn't seem like our friends in Beaverton got the jump on everyone because they thought of it first and everyone else was too dumb. Spira thought of it years earlier and others before that. It's just that they got the jump in the same way that the mob did with the booze trade during prohibition. If the cops were in on it, they got away with it. Were there rival gangs back then saying "Hey, we thought of that,too. Way before you did, in fact. We just thought we'd get busted."
Perhaps an imperfect analogy, since literal bribery didn't even have to take place. But something tells me that if Skechers comes out and their first gimmick is a spring - and they're directly calling it that - then it doesn't fly. They don't underwrite any big events or federations or employ any officials or even sponsor any A-list runners at this point in the theoretical story. They're a new gang trying to compete that the big guys accuse of cheating. No disrespect to Skechers (using them because they are a relatively recent entry into the market), just saying if someone came out of the blue with this imagine the army of lawyers in Oregon and what they'd be doing about it.
It took the big guys breaking the ice and paving the way. It's OK now. It wasn't 5 years ago. The ones who made it OK are going to have a head start. Fair? Read the rule again, but read the de facto rule between the lines. Is there one company that always seems to be on the cutting edge, or just one that gets to make the rules?