Informatica bundles Azul JDK starting 10.2.2 and will connect with Oracle using Azul JDK.
Oracle support would be able to speak about the impact of upgrading JAVA JDK/lib in relevant to Oracle client/server connectivity requirement.
Recently Informatica has released a Support Statement about JDK versions in conjunction with Informatica software (in particular, but not only, with the Informatica platform). It's formulated somewhat complicated. Please see here for details:
Informatica products use Oracle Java for all the supported OS platforms, but AIX. Before you install Informatica on AIX, you need to download and install the supported IBM Java version.
Starting from v9.6.1HF4, Informatica products are able to work with the JRE only. The JDK is no longer required because our software doesn't need to compile Java code at runtime anymore. The choice of removing the full JDK from the product is considered a security enhancement: i.e. the more components in a software package, the more risks coming from security holes in each one of them.
Those utilities that used to be available with the JDK and might still be useful for troubleshooting purposes (e.g. jstack), are made available in the $INFA_HOME/tools/debugtools/java/bin directory.
Effective in Informatica version 10.2.2/10.2.0HF2, Informatica platform supports Azul OpenJDK instead of Oracle Java. Azul OpenJDK is bundled with Informatica, and therefore you do not have to worry about issues like licensing. For additional information about Azul OpenJDK, please refer to the document Frequently Asked Questions Related to Usage of Java in Informatica Products.
So, as you can see, whatever the additional JRE/JDK you have on your system, that doesn't affect Informatica products. Although, having different Java's versions/flavours might cause issues if your environment get mixed up.