So if you updated a PC using the free upgrade offer and it only supports TPM 1.2, tomorrow it will no longer meet the minimum requirements for W10.
It is more logical that it should be that way. My guess is that this MS announcement was a heads up to their Enterprise Clients to be looking for this spec. when they buy new for their migration to W10. According to the experts who predict such things, Enterprise clients will be buying new and starting the migration to W10 starting in 2017. If TPM 2.0 becomes a minimum requirement it stands to reason that it will coincide with these client migrations. OEMs will have to comply or lose business. MS hardware for the Enterprise will no doubt be well positioned for this.