Summary
Despite being able to pick up seeds, plant, and bonemeal Torchflowers and Pitcher Crops, villagers do not harvest them. This is inconsistent with other villager behaviour, and leads them to occupy all farmland with crops they cannot replace.
Expected Results
Villagers should to harvest the crop once fully grown in order to replant, as with any other crop that they plant.
Actual Results
The Villagers fill up all available farmland, but never harvest, rendering the farmland unusable.
Confirmed, but if you think about, I believe this issue here is that villagers can plant and pick up torchflower seeds and pitcher pods in the first place; this statement of course goes against MC-261643, but allow me to elaborate.
When a torchflower crop fully grows, it turns into a torchflower. When a pitcher crop fully grows, it remains as a pitcher crop but drops a pitcher plant item upon being broken. Villagers cannot pick up torchflowers or pitcher plants, and therefore cannot plant them, and this makes sense because torchflowers and pitcher plants cannot be grown; why pick them up and plant them if they're already fully grown?
If villagers were able to harvest fully grown torchflower crops (torchflowers) and fully grown pitcher crops, it would leave torchflower and pitcher plant item entities on the ground. This may also lead to villagers harvesting fully grown torchflower crops that are not placed on farmland. Ultimately, it's not my decision, but I just thought this was worth mentioning.