I might get a slightly larger pot.
A larger pot will usually provide some insurance against lack of care and improper watering, etc that is common for beginners but the tree does not technically really need a larger pot. I can't actually see how deep that pot is in the photos but assume it is not ridiculously shallow.
IMHO. The tree really needs some of the roots at the base of the root ball cut so it can sit better in the pot. This just looks like sloppy potting up. Maybe a commercial operator trying to cut corners to save some time and bump up the profits or maybe a bored and underpaid staff member taking some short cuts that day.
As a beginner you will probably not feel comfortable removing roots from a tree at repotting so the larger pot will be easier and give the tree a better chance to survive long enough for you to learn and gain some confidence.
BTW, if you start asking about things like timing, when to do different bonsai techniques, it will be easier if we have some idea of your location. Some timing is very seasonal so knowing WHERE you are helps us advise WHEN is good. you can edit your personal profile so the info appears at each post and you don't need to remember to type it each time.