Once you have body-jumped through all five and die horrible deaths, then you go to the usual spawn screen. Maybe you have a set number of bots with you at anytime. This is a next step up from BF1's name dropping a casualty every time you die.
However, one way to circumvent this aspect that I thought of is this: if your character dies, you can almost immediately take control of the bot next to you. Relatively small number of players charging the trenches with you doesn't capture the spirit of the conflict. Going to spawn screen without having any sort of control isn't fun. Going up-and-over the trenches only to get shot right after isn't fun. There's more hiding, dying, than fighting in most combat theaters. If you don't go the fantasy WWI of Battlefield 1 route, then the weapons used are only bolt-action rifles, pistols and sometimes mounted machine guns. Random idea I had while reading your comment: We know that WWI as a setting is popular among devs and players alike, and one of the reasons why is because the combat is slow.