“DeFide” has given the
de fide 
documentation for this belief; all Catholics must assent to the teaching.
Through the parable you mention, the Lord teaches that the Kingdom of Heaven is open to all who respond to God’s grace to seek it, be they the first-in-line or latecomers. That is the “wage” of which the Lord is speaking. The Lord also says, “He [the Son of Man] will render to every one according to his works,” Matt. 16:27; and St. Paul teaches, “And every man shall receive his own reward, according to his own labour,” 1 Cor. 3:8; and “He who soweth sparingly shall also reap sparingly; and he that soweth in blessings shall also reap blessings,” 2 Cor. 9:6.
(You don’t really think that the Blessed Virgin Mary doesn’t experience a greater intensity of the Beatific Vision than you or I may, do you?

)