Let me guess, Japanese Performance mag right? Who for some reason asked Fensport who know next to nothing about Supras. The reason most people don't run more than 1.2BAR is not actually to do with breaking turbos, but the fact that you don't have sufficient fueling for any more than that, which will cause very high exhaust gas temps at the very least, which will in turn give your turbos a lot more grief. Plus the turbos are out of their efficiency range at 1.2BAR anyway.
If you have correct fueling and intercooling etc you can run more than 1.2BAR. I run 1.3, despite being out of their efficiency window you do still get more power than at 1.2.
Other errors in that Jap performance quote are that the Jspec has 280bhp (it doesn't, more like 310-320ish), that you should decat with a HKS downpipe (which will cause overboosting for sure on a jspec) and that you need a boost controller (you don't if you remove the cats boost will rise anyway). Oh, and that if you want to get 340bhp you need hybrid turbos and a fuel pump (but strangely no mention of anything to provide extra fueling!). Not true, a simple decat will get you there no problem at all.