Code customisations are completely unsupported and may break following an upgrade. That's not to say you shouldn't apply them, as long as you understand the implications, however, having a public dig at the support team for not providing support for something we do not provide support for, isn't really on.
It's a good idea to take notes on what you do OR have done to your forum (@everyone) so for example if you have a simple change as this done, you would make notes in a saveable file with info on what was done. After you upgrade check your notes and re-apply any required changes to have all your customization restored . If you have someone do the work for you ask them ahead of time for a change-log or quick notes on what they did (for your record after an upgrade).