I would have to agree as this being simply an add-on. I played CoH for nearly 10yrs.... This new planet is simply a new zone..... On CoH, new zones were part of the sub...... As well as the content associated with the new zone.
When CoH had an actual expansion you paid for it.... but it was an entire new "section" with 5 new zones, story line, and of course content.
There is a big difference between an add-on and an expansion when you are asking for people's money.,....
10 years? You played CoH for 10 years. The game was launched in North America on April 27, 2004 and in Europe (by NCsoft Europe) on February 4, 2005 with English, German and French language servers so you played at most 8 years, but i agree with your sentiments, CoH did expansions properly.