If you are currently leveraging any of the discontinued or disabled metrics in your existing content such as reports, alerts, dashboards etc., the VMware Aria Operations (formerly known as vRealize Operations)
Pre-Upgrade Readiness Assessment Tool can help you scan your content for these metrics and provide you recommended replacements in form of a pre-upgrade assessment report. This website provides you all these recommended replacements for the content (such as Metrics, Properties, Dashboards, Alerts etc.) which have been discontinued / disabled starting from vRealize Operations Manager 6.7.
You can use these recommendations to make appropriate changes to the content post upgrade.

VMware vRealize Operations 8.2.x
VMware vRealize Operations Manager 7.5.x
VMware vRealize Operations 8.3.x
VMware Aria Operations 8.12.x
VMware vRealize Operations 8.5.x
VMware vRealize Operations 8.x
VMware vRealize Operations 8.6.x
VMware vRealize Operations Manager 6.7.x
VMware vRealize Operations Manager 7.0.x
VMware vRealize Operations 8.10.x
VMware Aria Operations 8.14.x
VMware vRealize Operations 8.0.x
VMware vRealize Operations 8.1.x
VMware vRealize Operations 8.4.x

Click the link of the Pre-Upgrade Readiness Assessment Tool for the version of VMware Aria Operations you plan to upgrade to:
 

VMware Aria Operations Version	Pre-Upgrade Readiness Assessment Tool	Associated Knowledge Article
8.17.1	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for VMware Aria Operations 8.17.1 (97070)
8.16	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for VMware Aria Operations 8.16
8.14.x	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for VMware Aria Operations 8.14.x
8.12.x	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.12.x
8.10.2	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.10.2
8.10.1	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.10.1
8.10	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.10
8.6	VMware Downloads	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.6
8.5	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.5
8.4	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.4
8.3	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.3
8.2	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.2
8.1.x	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.1.x
8.0.x	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations 8.0.x
7.5	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations Manager 7.5
7.0	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations Manager 7.0
6.7	End of Life	Using the Pre-Upgrade Readiness Assessment Tool for vRealize Operations Manager 6.7

See the VMware Aria Operations Deprecated Metrics and Replacement Recommendations page for more information.