As said in the changeset summary, this is just temporary. These multiline strings won't even appear in the map when people browse it. 

If your newly drawn forests are better, then these will be eventually deleted after you finish drawing the forests by next week. But if the new forests you create is somehow worse, then I will use these multiline strings to recover the old versions of the forests.

Also, three things to consider before you even shout out the arguments "deleting because not everything in the national parks are forests" to justify yourself next time:
1. Really take a look at that example of Clarence Fahnestock Memorial State Park that I pointed out. None of those forests are erroneous. The issue that you pointed out (not everything in NPs are forests) indicates that those forests are not 100% accurate. Not 100% accurate doesn't mean erroneous. Many sea/ocean relations are not 100% accurate because there are some islands missing (which people haven't drawn), why not delete all of those oceans? You have made me repeat this statement for the 3rd time already, and I don't really want to do it the 4th time.
2. Were the members of every deleted forests and national park relations exactly the same? In the case of Nam Cat Tien area, that forest you deleted clearly included some natural lakes as it inner, while the national park boundary does not.
3. You deleted even a massive piece of forest along Dong Nai River (from Lam Dong's Cat Tien District all the way to Di Linh District), despite only a small section of it has Cat Tien NP boundaries.