mergeV requires key of 'new' to be quoted

When using text based queries the Antlr grammar does not seem to like certain keys being unquoted. In the example below, there will be a parse error thrown unless the key 'new' is in quotes. Note the other keys used are not quoted.

g.mergeV([id:'X1', name:'M1']).
option(Merge.onCreate,['new':true]).
option(Merge.onMatch,[year:2023]).
valueMap()
{'new': [True], 'year': [2023], 'name': ['M1']}