Although I do see that that bot has a very slight right wing bias I like it. It prevents the normalization of the use of literal propaganda outlets as news sources.
I have a suggestion that might be a good compromise.
The bot only comments on posts that are from less factual news sources or are from extreme ends of the spectrum.
On a post from the AP the bot would just not comment.
On a post from Alex Jones or RT the bot would post a warning.
That way there is less “spam”, but people are made aware when misinformation or propaganda is being pushed.
Also with such a system smaller biasses are less relevant and therefore become less important.