(1) It is estimated that the number of people who will visit Japan this year will reach 19 million.
(2) It is estimated that the number of people who visit Japan this year will reach 19 million.
Am I right in thinking who visit in (2) is simplified version of who will visit in (1). There is a similar sentence in 556 "Tense Simplification" of Practical English Usage by Michael Swan:
He says he'll give five pounds to anybody who finds his pen.