A UE not supporting EUTRA would not have read the MIB, SIB1 etc and would not even have tried attaching itself to the network. If it's a GSM or UMTS UE, it would have tried to attach to the GERAN or the UTRA network rather than the EUTRA network.
An LTE UE announces its inter-RAT capability through the Access Capability message. See the UE-EUTRA-Capability in 36.331. It lists what all bands it supports in the Supported Band List. Did that answer the question ?
interRAT-Parameters SEQUENCE {
utraFDD IRAT-ParametersUTRA-FDD OPTIONAL,
utraTDD128 IRAT-ParametersUTRA-TDD128 OPTIONAL,
utraTDD384 IRAT-ParametersUTRA-TDD384 OPTIONAL,
utraTDD768 IRAT-ParametersUTRA-TDD768 OPTIONAL,
geran IRAT-ParametersGERAN OPTIONAL,
cdma2000-HRPD IRAT-ParametersCDMA2000-HRPD OPTIONAL,
cdma2000-1xRTT IRAT-ParametersCDMA2000-1XRTT OPTIONAL
},