Does a reviewer get to know comments from previous reviewers? Most journals during second revision try to send the articles to reviewers who had reviewed the article before. But, if in case one such reviewer responds with a message that he cannot review the article this time, usually a new reviewer is requested to review the article. 

My question is will this new reviewer also get the reviewer comments from earlier reviewer along with the manuscript?
All publishers I reviewed a revision for so far did this, so I would expect this to be default.
In general, the information in the previous reviews might prove useful without the editor being able to predict this (otherwise, they could review the paper themselves).
Thus it would be unwise to withhold that information, unless there is a good reason for this (like a reviewer accidentally revealing confidential information).

Some specific examples where having the previous reviews is useful:


One purpose of reviewing a revision, if not the main one, is to evaluate whether the previous round of review was properly addressed and no new problems arose from the new material. A new reviewer may miss a problem the previous reviewers found, but they may be capable of telling whether it was properly addressed. (If all reviewers were perfect, why use more than one reviewer at all?)
Sometimes authors make weird changes in response to a review. It is much easier to properly evaluate these changes if you know what happened before. In particular, a reviewer can avoid or directly address the problem of making a suggestion that is in conflict with another reviewer’s suggestions.


Also note that often the authors’ response to a review contains the entire review as quotes anyway (and disentangling the two would be quite tedious for the journal).