Nope. Dropbox has never claimed they don't have access to your files, and you should generally assume that cloud providers are always looking through your data unless they explicitly claim otherwise (and maybe even if they do).
Dropbox has been in the news for scanning user files for years (eg, [1][2][3]). Note that the third link dates back to 2011; not a new issue.
If you do want to keep your data secure from the cloud provider, encrypt it yourself, or use a service that encrypts it before uploading using a key you provide (and with a client you trust not to be compromised). Spideroak makes a big play for this market[4], but I can't vouch for them.
[1]: http://www.pcworld.com/article/2048680/dropbox-takes-a-peek-...
[2]: https://www.extremetech.com/computing/179495-how-dropbox-kno...
[3]: https://readwrite.com/2011/04/20/how-to-keep-dropbox-employe...