They only recovered private keys where the nonce was used twice. This type of attack is known and mitigated in #Bitcoin for many years. ( see: deterministic nonces)

#Bitcoin Core uses RFC6979 deterministic nonces since 2014 and all alternative Wallet implementations should do also. So this should be not a problem for #Bitcoin.

RFC6979 git comit: https://github.com/bitcoin/bitcoin/commit/3060e360980f3e80db1d903085d759338ab27f4a