The guy who maintains SpinRite has a good write-up about TrueCrypt’s discontinuance. Basically, TC’s maintainers were tired after 10 years, and don’t trust anyone else to maintain their code. No NSA requests, backdoors, or security issues found. They just won’t be fixing bugs or developing anymore.

After the code audit is complete, it’s expected the 7.1a codebase will branch to a new product name, such as “OpenCrypt”. Until then, the final complete versions (7.1a) are available, including source code, for those who didn’t previously download it. I can confirm that at least the windows binary is the exact same binary as what I pulled down from TrueCrypt.org in 2012.

https://www.grc.com/misc/truecrypt/truecrypt.htm