Yes, children need more than a quick filling in in Reception. No they do not get this even in a good quality nursery or Reception class. If they did, they would not fall behind in large numbers in reading, and other subjects that demand reading and comprehension of a wide vocabulary, after age 8-9. The reality is that it is children's vocabulary and language exposure and not teaching them to read (by any means) that will determine their success in reading in the long run. Yes, they would be hobbled by not learning to read ever, but that skill alone will not guarantee success for them in school. It is language and vocabulary at the outset of school that determines who will fail and who will succeed -- demonstrating that early years attempts at filling in of the gap are inadequate. That is not just my opinion. Research has demonstrated that again and again.
Written media provide the richest reading experience of all, hands down, on that we can agree. However, most children will never read material that could widen their horizons to the extent that it could. They hit a wall at age 8-9 while others forge ahead at that stage. The dividing line lies in ease of comprehension although to some extent the persistence and resilience of individual children themselves will make a difference. Those with a wide vocabulary and a so-called intuitive grasp of language (which actually comes from constant exposure to it from the youngest ages) experience reading success while those who find it difficult and frustrating and slow generally do only what is necessary in order to do ok in school and gradually give up reading for pleasure or knowledge.
Try learning Russian by reading without vocabulary or knowledge of syntax, verbs, grammar, etc., MaizieD. See how far that will get you when you attempt to read something that demands a wide vocabulary and exposure to complex sentences; when the rules of oral Russian are internalised it becomes much easier to comprehend what you're reading.
When teaching children who are English language learners to read you will be more successful in the long run if you teach them to read in their first language either before transitioning to English or simultaneously with English reading. 'Effective Reading Programmes For English Language Learners: A Best Evidence Synthesis' illustrates my point. When teaching children reading in any language, longer exposure to good quality oral language bodes best for their success. The paper I linked to (which is a synthesis of good quality research, as opposed to the report of a single experiment) states clearly that best evidence strongly indicates that ESL children's success in learning to read English (including success at later stages of school) can be predicted by the quality and quantity of their vocabulary in their first language (along with the recommendation that reading in the first language plus reading in English, or English following hot on the heels of the first language should be the approach). The implications should be obvious to you, but here they are -- language and vocabulary are essential foundations of learning to read initially and progressing to development of higher level reading skills.
I didn't consciously teach my 3-4.5 year olds to read. They surprised me, and I worried about them whether they would be bored in school, whether they would neglect maths for instance, when the time came to work at something that might not come to them as easily as reading did, whether someone would misguidedly make some sort of big thing about it and have them thinking they were freaks of some kind. Children need to know how to learn, to experience logical thought and learn how to approach challenges in a methodical way phonics teaches those skills in spades. I worried that my children had missed out on that 'learning to learn' experience. I didn't have to. I recognised that children learn in a myriad of different ways.