Stuff like that happens every few years on larger scale and sometimes multiple times a year on smaller scale (e.g. part of Berlin local trains not going because of it).
A lot of this sabotage comes from people trying to steal cables, but then also sometimes giving up in the process.
Then there a climate crazed people which in a twisted way blame the trains for partially causing the climate crisis because they are too expensive...
There are also two or three other radicalized movements which in twisted and less twisted ways use the DB as a representative for the "evil state/system" and then jump from there to sabotaging the train service, not limited to the DB (sounds stupid? it is, but happens anyway).
The only thing special in this case is how many lines had been affected, not that it happened.