Well if the bottom leaves area diseased or sick then it's okay to trim. I saw photo from your other posts and some of the leaves were yellow, so those are okay to go. There will be new "suckers" that will grow out from the parts that are trimmed. Looks like you have some suckers on the top growing right now. The suckers will develop into a new stem and will be like new a plant. People tend to trim suckers to keep the plant from being too bushy and speed up the ripening of fruits. (Some claim it yield bigger harvest, which I don't agree with.)

If you are growing vertical on a single stakes like that though, you might not want too many suckers since it's harder to support multiple tomato vines, but if you have cages for them it would be alright to have some suckers.

For me, I believe aside from the suckers, and unless the plant is diseased or lacking airflow, too much trimming is probably counter productive. The leaves are there to make glucose and that is what will contribute to a sweeter and more nutritious fruit.

What are they potted in? If garden soil, change out to potting mix.

Also need much larger pots to grow to maturity.

In addition, they are leggy; they need much more light