These are miles upgrades.
In this case J is available in BOTH segments individually.
What you are saying is that from now on if you fly multi segments they ALL have to clear and be available as the original route? Did you ever experience that in ANY airlines including TK? Why stop there some fares must be available on a round-trip basis and can't always be combined together so maybe in some cases you'll have to clear for the whole trip! This doesn't sound absurd to you?
Upgrades and awards never followed these rules as they have a few simple rules in place - you're confirmed in eligible class and J is available. If they add "and you must clear for the whole trip always or only on your birthday" that's ok as long as it's written and everyone knows about it (of course I will no longer fly with them). I bought specific fare codes so I can upgrade. I did my part and I think there is no other name for it but a scam. Let's even go further with this. Do you think it's ok if you book an H fare (or any other upgrade-eligible for that matter) for example and then they'll say "actually this H fare is different and it was a promotional H fare and you can't use it to upgrade".
The TK agents said that even if I buy only one way for the first segment I won't be able to upgrade.