Yes, it does. By default, Ec2 instances launched in EC2-Classic have full outbound access. So, the Ec2 instance can connect to your Oracle DB Provided your Oracle DB is accessible over the internet (in other words, your Oracle DB has a public IP address and you have firewall rules configured on your end to allow inbound access to Oracle DB).
If you Oracle DB is in a private network, then you need proxy server or SSH tunnel (or something similar) to connect to the instance.
Overall, there is no limitation on EC2 side.