*Replacement product has been updated. Please refer to next line for current functionally equivalent product.
It means that originally the MS220 replacement was considered to be the MS225, but when the MS120 was released, the MS220 replacement is now considered to be the MS120.
Both the MS225 and MS120 are current products without an end of sale announced.
Personally I would say that the MS120 is the direct replacement for MS220 8 port switches, whereas the MS210 could be the direct replacement for MS220 24 and 48 port switches as the MS220 and MS210 both support the (now discontinued) RPS2300. However the MS210 supports stacking, whereas the MS220 did not, so the MS120-24 and 48 could be considered direct replacements.
The MS225 is better than the MS220 in every way, adding both stacking and SFP+ ports in place of the SFP ports on the MS220.