An outproxy could fuck you over sure, but in the same ways as a VPN getting served with a warrant can, like say Proton VPN, or, a Tor exit/entry node that's actually being run as some kind of Law Enforcement / Intelligence Service honeypot.
Difference is that I2P packets themselves are, again, arguably, in my estimation... more encrypted, more difficult to disentangle and backtrace, than a VPN shunted traffic, or even Tor, if you're bouncing through enough comprimised, honey pot nodes.