Are the signcryption and the authenticated encryption same?
Your finding is correct. From your links;

In cryptography, signcryption is a public-key primitive that simultaneously performs the functions of both digital signature and encryption.
Authenticated encryption (AE) and authenticated encryption with associated data (AEAD) are forms of encryption which simultaneously assure the confidentiality and authenticity of data.

The signing in signcryption is performed with the private key operation. This can provide non-repudation since only the owner of the private key can sign.
The authentication in AE is performed with a shared key between parties. This cannot provide non-repudation since both parties have the key. We can say that the authenticity is mutual.