Well, if you remove the ripe fruit, you will start over again with blossoms...but I doubt it will convince the tree of a cycle. It is showing you it's happy enough to over perform, be happy for it, I would think.

Let it be, the tree knows what to do, you just feed, give water and watch for pests. Is it growing in a container? Any pictures?

I didn't explain my question clearly enough. If the tree is simultaneously trying to ripen fruit and produce blossom, might it end up not doing either very well? This year's crop is definitely smaller and the fruit poorer quality than when the tree had a clear seasonal cycle.

You can always thin the crop to get larger size fruit.

The information given is too vague. I think your environment plays a big part in the life cycle of the tree. If your tree is happy with its conditions, it is going to bloom whenever it wants and set fruit. You don't specify which type of mandarin you are referring to, the country you are in or which type of fertilizer you use. Maybe something you have done to the tree has caused the tree to change it's growing habits.

Keep in mind color change has more to do with the temperature than ripeness.