One day if receiving addresses are crackable, then there may be information leakage, like how the generating key had a certain pattern that classifies a group of users. For example, a certain range of "random" keys that weren't random. But that's a very long distance into the future, hopefully.
To turn a receiving address back in to a private key requires reversing a RIPEMD-160, SHA256, and an elliptic curve multiplication. Even advanced quantum computers which are still decades away will not be able to achieve this. And even if we ever get to a stage that SHA256 can be broken, then an attacker can at most find a collision. Given that there are 2
96 public keys per address (on average), then that's still far too many possibilities to draw any meaningful conclusions from. In short, this is not a concern.
Your other point regarding Electrum is an important one, though. If OP starts going around looking up this address on various block explorers or querying it through light wallets, then it links his IP address to that bitcoin address. Whether or not that information ever finds its way back to the person he is concerned about is another matter, though.