Let's step into the minefield ^^.
Is there a distinction, philosophically or grammatically, between definite articles and pronouns that makes sense of my friends’ position?
Regarding the first part of your question, one must first say that the use of an article in front of a first name is a regional peculiarity that in northern Germany can even be taken as an insult.
See this question or this one (in german)
Quoting the second one
Wenn die Lotte und die Rosie Durchfall hatten, musste der Veterinär kommen, denn dann waren die Kühe krank.
If (die) Lotte and (die) Rosie had diarrhea, the vet had to come because then the cows were sick.
But back to your question. You could say your friends are right in a way. Let's say one of your friends was called Klaus-Maria. Always called Maria. Would it be polite to call him "die Maria"? Or is it "der Maria"? And what do you do with you new chinese colleague "Zhenqi", who wrote you an email last week and you never met in person? Man? Woman?
You can apply that to everyone. If you know about a person how they want to be addressed, you can use the corresponding article. In all other cases you could insult them in the worst case. Of course you can roll your eyes and say "We have always done it that way, he/she/it shouldn't make such a fuss." Or you could be considerate.
Is there really a movement to eliminate gender from the German language to some degree?
Well, many (especially those who are against it) say yes, but actually no. It's more about expanding the language. Nothing should be taken away from anyone, but language habits should be broken in order to represent all genders equally. One of the biggest points of contention is the generic masculine, which has been discussed here often enough.
An englisch teacher will always be a german "Lehrer" or "Lehrerin" - and today it's already a "LehrerIn / Lehrer:in / Lehrer*in / etc". In the future it might be possible to translate it as "Lehreron / Lehrerx". Always depending on the context.
Unlike the word "hen", which was officially introduced in Swedish in 2015 - and which has positive effects -, there is no neutral pronoun in German that is generally accepted (yet). However, there are a number of suggestions for gender neutral pronouns
sel, han, dey, em
dai, dier, del
But, there are also a number of laws and official regulations on gender-equitable language in German-speaking countries. For example the "Leitfaden für gendersensible Sprache bei der Hansestadt Lübeck" says
Do not use the general clause “that only the
masculine form is used and all other genders are included ”.
Avoid role clichés and stereotypes such as mother-child parking lots
or diaper-changing room for mothers. The same applies to language images such as need for a man or Milkmaid bill.
When using images, make a careful selection under the Asking who you want to reach and how all genders are taken into account
Include the 3rd gender option. At the Hanseatic City of Lübeck, in
In writing, the gender colon is generally used or formulated in a gender-neutral manner.
Nonetheless, there seems to be a change in society. You can hear gender speech on TV and the news. More and more advertisers are also using it. Twitter users and Bloggers write their preferred pronouns in the profiles.
All of these are not yet a complete social change, but indications that we are in this. We don't know what will happen in the end, but something will happen. Whether one side or the other likes it or not.