Microsoft has recently released .NET Framework 4.6.1 as a recommended update for Windows. What they haven’t released however, is the fact that it isn’t yet supported on the Exchange compatibility matrix.
With the update being so new, if you decide to install it at this stage you could risk breaking your Exchange on premise install. The premature introduction of this software will subsequently require its lengthy and complex removal. We recommend that you take this opportunity to verify your current WSUS approvals and perfect your patch cycle to prevent any future issues.
The .NET Framework 4.6.1 will no doubt be fully supported by Exchange in the near future, however in the interim, BDS would advise against its deployment on any Exchange server.
Unless of course you like a gamble?