They are tempering expectations, but they're clearly happy about the progress that is being made. Alpine is 5th fastest at the moment and they were no more than 3 tenths per lap slower than Merc/Ferrari at Bahrain and Saudi respectively
So I can see why they are talking about fighting with the top 4 teams by the end of the season. It seems entirely plausible if they're very confident about the avenue of development that they have found, and believe there is lots of untapped potential (due to not getting onto this trajectory early enough)