If you restore it using wallet seed, all previous transactions will appear, but some settings will disappear, such as some of the tokens you hid or comments you left.
If you don't remember wallet seed, all your coins will be lost.
On trust wallet, sometimes if you update your wallet or even import your wallet in another device, some of the transaction history might not appear visible on the app. I have experienced this before while using trust wallet.
This is not supposed to happen, as deleting data does not change anything in the wallet, the only things that disappear are your previous settings, such as hiding some tokens or the blockchain.
After reading the topic again, I think that the user may ask about unconfirmed transactions or those transactions that broadcasts but wants to delete before confirming them.