I thought your licenses (wether it was an old or new one) will not be expired. Only the 1-year upgrade authority will be expired and you should buy a new 1-year access right for upgrading your Threads.
Thus, if you're an old license holder, you don't have to worry about those terms on the new license since you do not have a new license. For those old license holders, all you have to do is to decide to keep on upgrading your Threads with 75% discount (that's $31.25) per year or not. If you choose not to upgrade, you can still use your Threads (1 license, installed several instances but under one same domain) under the old license you held.
Is that right?