That may be true, in other cases, however in my case it's placed my progress back to the beginning. In the screenshot the 23rd tier is selected at the reward bars at the bottom, however at the top it's displaying tier 22. Also you may notice the progress under the find opponents button, is at the beginning, because it's just reset after I finished the 22nd just before taking the screenshot.
Also, this would be my 3r'd time completing this tier.