I can tell you from having seen pretty obvious stuff in the CBA that should have been fixed, that still isn't fixed, that army of lawyers isn't going through and thinking of all possible scenarios. Nor should they necessarily have to be doing that. Their foci are "does this pass the legalese test if we have to go argue it" and "does this not hurt the owners" and "if this could hurt the owners, how do we fix that."
Teams utilizing the cap via LTIR come playoff time? That's not a "benefits the players at the direct expense of the teams" thing so they never would have looked at it.
Guys who can still sign long contracts at older ages that are otherwise legal, who can then bail out on the final few years and the team can skip the cap hit? Still perfectly legal, completely foreseeable [and if anything I'm shocked no one has tested that yet], and either no one thought about it or someone thought about it and no one thought "yeah, that could happen ... let's guard against that." But goddamn it, we stopped 22-year old Quinn Hughes from signing a 10-year contract to age 32 when he's probably still going to be playing. That was the real problem right there.
I don't think Chicago could have possibly known in 2013 that 2 years later, Kane was going to have a broken collarbone in late February and land on LTIR. ust like I don't think Tampa possibly knew in 2013 that Nikita Kucherov, who was only just starting his playing career in North America, was going to break out and be a 2-time (soon to be 3-time) 40-goal, 4-time 100-point guy and was going to have to have hip surgery in late 2020 that was going to put him out for all of a shortened 2021 season.
I do think Chicago long before 2013 knew Hossa wasn't going to be playing after 2017, and the cap re-cap capture re-cap-recapture capture deferred cap penalties imposed changed the original plan on how that was going to happen, but Kane in 2015 and Kucherov in 2021 were much more unexpected opportunities - and even with Kane, he came back ahead of schedule and ahead of everyone's expectations and the angst over him was much more in hindsight than real-time - than they were some brilliant vision by anyone as to what would happen 3, 5, 7, 8 or more years out.