title: Huge number of package changes when using conda to upgrade from tensorflow 1.14.0 to 2.2.0
body: <p>I'm trying to update tensorflow within one of my conda environments. But, each time I get set to update, the preview shows far more packages being upgraded/added/removed than I believe is anywhere near reasonable. I want to figure out whether I have a faulty understanding of:</p>
  <ul>
  <li><p>Package interdependency, so should just let everything proceed, because it is fine.</p>
  </li>
  <li><p>What I'm doing, so need to proceed cautiously in order to understand how I'm changing my environment.</p>
  </li>
  </ul>
  <p>When I examine my current environment (i.e. <code>dnn_py3</code>), I see:</p>
  <pre><code>(dnn_py3) me@Home:~$ conda list
  # packages in environment at /home/me/anaconda3/envs/dnn_py3:
  #
  # Name                    Version                   Build  Channel
  ...
  tensorboard               1.14.0           py37hf484d3e_0    anaconda
  tensorflow                1.14.0          gpu_py37h4491b45_0    anaconda
  tensorflow-base           1.14.0          gpu_py37h8d69cac_0    anaconda
  tensorflow-estimator      1.14.0                     py_0    anaconda
  tensorflow-gpu            1.14.0               h0d30ee6_0    anaconda
  </code></pre>
  <p>I want to upgrade to tensorflow 2.2.0</p>
  <p>When I enter</p>
  <pre><code>(dnn_py3) me@Home:~$ conda update tensorflow-gpu
  </code></pre>
  <p>or</p>
  <pre><code>(dnn_py3) me@Home:~$ conda update -n dnn_py3 tensorflow-gpu
  </code></pre>
  <p>I get an extremely excessive (I think) list of downloads, new installs, removals, superceded packages and downloads, which I've summarized here:</p>
  <pre><code>Summary of Changes:
  122 - download packages
  5 - installs (none actually tensorflow !?)
  24 - removals
  263 - upgrades
  140 - updates
  </code></pre>
  <p>I currently use tensorflow 1.14 in my environment, so I don't understand why this upgrade requires so much to be done. I expected to see only 1 upgrade (for tensorflow-gpu) and, possibly, a small number of other changes - nothing like the avalanche of proposed changes that I do see.</p>
  <p>Since what I see differs so greatly from what I expect, I'd like to understand what's going on, before proceeding.</p>