It seems to only happen with his President skin but whatever voice line I pick on the loadout never saves. It always defaults back to the first one.
I not 100% but I have had this happen to me on other heroes. Think this happens you don’t save them by that I mean you have to change from presets 1 to 2 etc and a game loads.
Edit: So I tested this today. I managed to get the issue working on my Master Dreadmachine Mal’Ganis. This is on my #2 preset; I change the voice line to the 2nd voice line, then I changed to my #1 preset and went back to #2 preset and it changed to the 1st voice line.
Then my game loaded while I was trying this. It WAS the 2nd voice line (After the match it still showed the 1st voice line in my preset though.
So the way I managed to get it to work was to change my voice line then EXIT the preselect menu and it stays as the 2nd voice line. It will however change to 1st voice line if I go back in, select the voice menu and swap presets again.
If you are having this issue with the Neo-pesant skin it might be an issue with skins that came with the hero release? Anyway I hope this helps and I hope they fix this minor issue
I have the same exact issue, it’s annoying to have to change it every time I play Anduin
I get that too. I just wanna spam “I’m out of cards” 
This has been a bug for over a year.
Is it that complex to make sure that the voice line players select stay selected?
All of the Neo skins seem to have the problem.
You pick a voice line, finish playing, & if you check the loadout resets the voice line to the first line.
I’m out of cards is a great line, but I can’t keep that line every match if I want to use the Neo skins. The plain skins it is fine, only the Neo skins forget between matches.
It’s really sad that this is still a bug a year later & people who buy the Neo skins can only count on 1 voice line ever.
It’s 2024 and this bug still isn’t fixed 
Neo Anduin keeps forgetting that he’s out of cards.