Will adding lots of new content (blog posts) all in one day make my site fall in rank?

It looks like Content blast to Google, Adding 2/3 fresh content daily to newly created site is normal.

Personally, I do not think so. My sites went up and down sometimes without me doing anything also. The ranking is closely related to what other is doing on their site as well. Having more post should help in future as you have a lot more content. You shouldn't need to worry about the small fluctuation in ranking.

google should be crazy if they think each new website/blog should start posting 5-10 posts only. what do they know if you are a huge company ready with writers publishing 60 posts per day.

Make your visitors come back again and again with posting new content daily.Not all of them in one day.

Here is the issue. You are not getting any negative points for what you are doing however you are not getting as much benefit as you could. By releasing all at once you are only notifying Google of site changes that day which if you do not release content often enough you will not be notifying Google of changes as often, so they will not crawl your site as much. Also it will make your blog look more personal than professional because a professional publication keeps updated often for its readers.

If you are using WordPress and many other blogging platforms you should be able to schedule your articles to post on different days and times. I would try to space them out evenly throughout the month to appear as much as possible like a news or media site. Also if you are not doing social media with these posts you should be as well. By releasing them more evenly you are also spreading your social media more evenly. The benefits can go on and on but these are important things to think about when trying to rank a blog.

I also agree with the spacing out your content updates. It's perfectly fine if you plan on adding that much content every day. Usually it's better use of time to schedule the posts for future days.

This way, you can bust out a bunch of articles and just schedule them to post over the next 30 days. You can then use the time to work on other things. Remember, diversification is key.

Yes, posting a new article will trigger a temporary drop in rankings. Posting lots of new articles can trigger a drop large enough to be noticed.

The drop happens because the new page that the post is on gets linked to, which take link juice from your other pages, but for the first few crawls that new page has no authority what-so-ever. However, it doesn't take long for that page to take on the authority of your site. Once this happens (usually within 2 days) the drop should go away completely.

This drop is not a penalty or a spam trigger, it it just a result of how the PR system works. Adding a new page to your site = a temporary drop in authority.