The only change between Openvpn-2.4.0-I601 to -I602 was Openssl-1.0.2i to -1.0.2k
OpenVPN wroteInstaller version I602 includes OpenSSL 1.0.2k
See:
https://openvpn.net/index.php/open-source/downloads.html
The developers are also considering adding git tags with the I60x indicator, thanks for spotting this.