A signed message may be required for several reasons:
1. account hacked (need to recover)
2. Proof of ownership if anyone asks to prove the ownership for any specific reason
3. taking loan
4. Using escrow
5. Trading
For these reasons, the person can verify by any wallet used at least 3 months ago. If there are multiple wallets staked then the user is free to use any of them. But no one is bound to verify whether the user has used how many wallets and which has been revoked/deleted. While any previous wallet signed means the user has ownership. If any wallet has no ownership or has been hacked, then it is the user's responsibility to remove the wallet where the person posted. The person shouldn't have any space posted in that wallet.