The comparison was to point out the differences of CPUs used in the micro systems.  That would only explained the reason for higher than average temps comparing to previous models, a factor for you to take into consideration.  But it wasn't accounted for the rest of described unusual fan surges and the thermal fluctuation could be triggered by something else.  Dell Optimizer has thermal control options which may calm the fan down a bit.  But it won't work with Linux.  Open up a new machine to check condition of thermal paste doesn't seem right neither.  Only you can decide what is acceptable for you and taking appropriate action to get it resolve.  Especially, if you just get this machine recently and having option to return/exchange for a proper functioning system.  
  Hello,  just got a new Optiplex Micro 7010, with the midrange i5-13500T cpu. Compared to the other Optiplex Micro I own (i have several) this one gets quite hot. Even just staying idle, in the BIOS settings page, the others are barely above room temperature, this one gets *hot* and the fan is spinning and annoyingly adjusting all the time.  I installed a Linux distribution (SLES), the same I have on the other Optiplex, and while it sits idling at around 40C, with the fan quite hearable, even just a single Google Meet call, which I normally do without any issue on a 6 cores i5 3070 micro, was enough to bring all the cores to the 80C neighborhood, and the fan screaming. Haven't even tried with some actual full load. I have about a dozen optiplex micros, of various generations, and while some do get warm under load, none gets nearly this warm for a small-ish amount of work, or at idle. Is the 7010 micro thermal management seriously underpowered in general or there's something with my copy? The Dell diagnostics end all the tests with success. I also have a SFF 7010, with the I5-13500, which is totally silent (okay, it's much bigger, still....)  
New Optiplex Micro 7010 gets quite *hot*, fan spinning even when idle.