Its exactly the argument.
It was brought up specifically. So whats the issue?
No they really couldnt. How would you rectify the issue of people just stockpiling all their sidereal to just spend on the new gear? You would either have to create a new currency and downgrade your sidereals to that new currency and make all the items that cost sidereal into that new essence, create a new currency while leaving the sidereals to be used for what they are already used for, or wipe everyone progress clean every phase.
Its not an issue.
Then get a job at Blizzard and fix it in 30 minutes. Most people that say this dont actually have a solution. Just like the other person saying sidereals are already in place and plaguestones didnt need to be brought in, yet you cant just have people stockpiling their sidereals to buy new gear. You have to reset it in some way.
You cant say its a simple fix, yet say they are keeping things because they are lazy. If people gravitate toward the path of least resistance then the simple fix cant be that simple and actually involve more work.