As long as the wallet is in place before bitcoin core has a chance to prune anything, it will work properly
Reference Link

Let me explain. Basically here is a simplified version of how bitcoind stores wallet transactions:

• wallet.dat contains Private Keys | Synced upto Block | Wallet transactions
• When new block arrives, bitcoind looks for wallet transactions in the block and adds the ones found into wallet.dat and also updates Synced upto Block field
• In prune mode, older block data is removed, nothing happens to wallet.dat

So if you activate prune mode on a running node, or boot up an old bitcoin node everything should work.
However, if you import an older wallet.dat into already running pruned node, it has to rescan everything from Synced upto Block to find the transactions. This may not be possible due to missing block data