As far as I know the only reason to not do any balance changes before release(wipe) is that it was promised a very long time ago.
There is few things I want to point out:
every change to cards invalidate all leader-boards
every change to cards make it difficult to run replays, EA make it so you can not open them at all
From my point of view doing changes now will limit these problems after release.
Some changes like changing HP, or cost of something are for me just 1 number, and I may even be able to keep replays compatibility with some background work for these changes, so my suggestion is to start with these changes now. (more complicated thing will not be included for now)
Before someone start asking why to do balance changes, if there are crashes, lost cards, etc. I try to explain it this way all these things are impossible to reproduce for me, so only source of information are players that experience them, and based on "https://docs.google.com/forms/d/e/1FAIpQLScpTeA_Lv1b1M0imSel-B8UgYsP9evdmj-DiRQ-x1vAFwLZAw/viewform?usp=pp_url" most of players do not even say us when it happen so they are really hard to track without your help. Balance changes on the other hand mean for us "just" validate community decision and change 1 value.
https://discord.gg/GZKKMqH I do not think the results will change significantly without any progress, so here is the link to discord server that will be related to balancing the game. I decided for discord (as first try) because of the advanteges mentioned, mainly rules enforcing.