Submitted by deliriusz, also found by zhaojie and p0wd3r
https://github.com/code-423n4/2023-11-zetachain/blob/b237708ed5e86f12c4bddabddfd42f001e81941a/repos/node/x/crosschain/keeper/keeper_cross_chain_tx_vote_outbound_tx.go#L61-L226 
When the cross chain transaction is reverted on destination chain, the revert transaction is processed on source chain, and the remaining amount of Zeta tokens, excluding fees is returned to the CCTX sender. According to the code comment in /x/crosschain/keeper/keeper_cross_chain_tx_vote_outbound_tx.go:
The flow is:
There are 3 possibilities when it may fail:
If if fails, the transaction state is set to Aborted in  x/crosschain/keeper/keepercrosschaintxvoteoutboundtx.go, and it wont be processed:
In wont be processed again.
And because only Connector can mint the tokens, the funds are lost without anyone able to mint them for the user.
Concerning maxSupply, its set to uint256.max during contract creation, however its adjustable by TSS to any value:
User funds lost in case that revert transaction reverts on source chain.
Lets take following example:
lumtis (Zetachain) confirmed via duplicate Issue #245
