Previously, a foreclosing plaintiff could sue whenever they wanted without worry about statute of limitations constraints so long as payments remained due under the loan. When they sued, they'd accelerate the loan and declare the entire amount due for purposes of the lawsuit. However, if something went wrong in the lawsuit, they'd deaccelerate the loan and then, start the process again without fear of the 6 year statute of limitations on foreclosure actions blocking their case and having the lien removed?

Simply, plaintiff had the unilateral authority to deaccelerate the loan. No more. 

Now, CPLR 203(h) clarifies "that upon accrual of a cause of action, the aggrieved party - meaning

the party with the right to commence an action and interpose a claim may not unilaterally extend its own time to assert its own claim."

This is a game changer - there are going to be a lot of cases dismissed on statute of limitations grounds moving forward in New York State.