You just removed its' primary source of producing sustenance for itself. What is going on at the root end?

I thought roots were the source of sustenance for a plant, since that
is how they absorb nutrients? the roots are looking healthy and growing, especially considering it only had like one or two roots when i first bought it. I'll include a pic.

The leaves perform photosynthesis.

of course! :) however, the leaves were turning yellow and brown,
a sign they were dying. not sure how useful it would have been to
keep them on. Also, cutting off the shoots (leaves) on lucky bamboo
is how one propogates it, so again not sure there was much damage
done as it is a common way to propagate this plant. anywho, the good
news is it appears the stalk is creating more shoots (leaves), so hopefully it should be back to its happy plant cycle of life in no time!

Taking cuttings from a vigorous, healthy donor plant is entirely different from removing the only few leaves from a struggling plant. How are things looking at the root end now? What kind of water is being used? Dracaenas are sensitive to several chemicals commonly found in tap water, which is also usually a wrong PH for healthy plants of almost any genus. This (among many other things) can cause chlorosis (leaves that turn yellow because they are no longer able to phytosynthesize.)

Unless some form of nutrients are added to the water at least occasionally (and in a very diluted dose,) there's no sustenance for the roots to provide to the rest of the plant, but leaves are needed to complete the plants' cycle of life. The pic doesn't show clearly, was it the newest leaf that was turning yellow/brown? Hopefully there's enough chlorophyll in the stem to keep this plant alive. Sending good vibes!

If you ask on the house plant forum also, you should get more responses, (though be prepared to likely be advised to plant your stem in a pot of 'soil.') This forum's much more slow.

Here is a link that might be useful: common Dracaena maladies

Thank you so much for the info and good vibes! :) this guy (and my other lucky bamboo) are currently in a glass filled with bottled water. I do want
to plant them as I hear they thrive when planted. when I bought my lucky bamboo I decided to keep them in water first so they could grow some roots
and hopefully be a bit healthier before I plant them. I have 3 other LB that are
ready to be planted I think. any advice on what type of soil?? I didn't think to post in the houseplant forum thank you for that!

Glad to share info. I'm sure you'll do the same when an opportunity presents itself. People who like to water plants often can have difficulties with bagged potting soils because they are usually comprised of all small particles that compact so closely together that there are no tiny air pockets throughout. In "soil," roots need air as well as moisture, or they can rot. Adding more perlite or some bark can help, or using something more chunky to begin with. This info might be helpful to get started.