I am studying for some Cisco Security certifications because my job needs it and I have seen there that they are talking already or at least being prepared for what they call post quantum computers encryption and algorithms type. This mean that this Sha-256 most likely can be cracked in 10-20 years as that was the time frame in the book assumed when we will be needing these next generation encryption and algorithms. I don't know why it was made public but for the moment it is one of the very strong encryption algorithms as in VPN-Virtual Private Networks site to site connections we are using it as one of the best encryption algorithm, the SHA-256.
You can read more here if you are interested in algorithms security.
https://www.cisco.com/c/en/us/about/trust-center/post-quantum-cryptography.htmlThis is not true. SHA256 is not an encryption algorithm, and the speedup for it when using QC is not as significant as asymmetric algorithms. SHA256 will not be weakened significantly to require a change in algorithm anytime soon, but ECDSA would be entirely different when QC is viable.
One more thing, VPN are not using SHA256 for encryption of data. For the majority of them, they are using AES or similar asymmetric algorithms. SHA256 is a hashing algorithm.