I'm not sure how either of these articles support your point.
Your first article is someone criticizing prior efforts by others to reduce public education funding. The only person using the word "defund" is the author. Though interestingly, there is a mention of conservative attacks on programs like sociology, anthropology, minority studies, and gender studies. I assure you that many conservatives really do want to abolish funding for those programs.
The second article is a single person using the word "defund" to describe Obama's reduction of military spending. Again, somebody using the word to describe somebody else's actions.
Interestingly, both of those articles are by people who oppose defunding. Perhaps they used that word precisely because it implies "remove funding entirely", which has an exaggerated emotional impact?
In any case, neither example is the same thing as a large social movement using it as a slogan, especially when that movement publishes things like "Yes, We Mean Literally Abolish the Police": https://www.nytimes.com/2020/06/12/opinion/sunday/floyd-abol...
When things like that appear in the New York Times, is it so unreasonable for people to take their word for it? Or should we keep insisting that they don't really mean it?
And before you tell me that that's just one person's opinion, I'll just point out that so were both of your references, and those are the opinions of people who aren't even supporters of those movements. The "defund the police" movement has its own people using the term and saying "yes, we mean literally abolish the police".
The first article also quotes someone else saying defund. Eliminating sociology, history, anthropology, and language aren't mainstream conservative positions. Minority studies and gender studies maybe.
I picked 2 old articles from different political tribes to show it isn't new or just 1 tribe. Defund the Pentagon is a slogan now. Bernie Sanders[1] and Barbara Lee[2] proposed cutting the military budget by 10% and called it defunding.
I don't see anyone saying defund can't mean abolish. But most people who mean abolish say abolish because defund can mean reduce funding.
It's unreasonable to listen to people on the fringe of a movement and ignore the majority. It's unreasonable to read NYT opinion pieces and ignore NYT news pieces.[3] It's unreasonable to ignore actual legislation. It's unreasonable to ignore all the top search results.
[1] https://www.alternet.org/2012/10/how-higher-education-us-was...
[2] https://www.realclearpolitics.com/articles/2014/03/10/defund...