@Vanifica
have in mind you always can distribute new loadingtips to the game itself.
Just write an issue or make an PR on Github:
https://github.com/FAForever/fa
Depending on your effort and the quality of your tips it would be also possible to patch the game
and make it possible to load tips from a mod before the loading screen is displayed.
(i would not like that, good tips should be available from the default game)
Last "and" least you can make a .SCD mod. That means you make an archive with the changed files and put it direcly as *.scd file into the gamedata directory. This will overwrite the original files before loading the game.
But i would not recommend that. Since it will overwrite the original files it must be fixed after every game patch.
Including your tips to the game itself (Git-Hub) would be the best option!