There aren't any planned changes but I can't gaurantee the exact pixel heights will stay the same because the implementation doesn't clamp the height to any exact pixel size, it's based on text height, padding, margins, etc., so if we end up fixing some bug that affects any of that, the heights might end up changing slightly again.
Bug 2059425 Comment 13 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
There aren't any planned changes but I can't guarantee the exact pixel heights will stay the same because the implementation doesn't clamp the height to any exact pixel size, it's based on text height, padding, margins, etc., so if we end up fixing some bug that affects any of that, the heights might end up changing slightly again.